Management of non-functioning pituitary adenomas: surgery

The effect of preoperative TSH levels on perioperative complications in patients undergoing pituitary surgery

INTRODUCTION

Pituitary surgery involves special conditions for the anaesthetist due to the anatomical localisation and the role of the pituitary gland in hormonal balance. The aim of this study was to retrospectively investigate the effect of TSH levels on perioperative complication rates in patients undergoing pituitary surgery.

METHODS

In this study, patients who underwent pituitary surgery at Izmir Katip Celebi University Ataturk Training and Research Hospital between January 2017 and November 2022 were retrospectively screened. Two patients out of the 137 were excluded from the study as they underwent simultaneous aneurysm surgery along with pituitary tumor surgery. A total of 135 patients meeting the criteria were analyzed. Patients were divided into three groups according to TSH levels. Perioperative complication rates and mortality rates were compared between the three groups.

FINDINGS

The study included a total of 135 patients, with an age range of 16-76 years. Among the groups with low-normal-high TSH levels, there were no statistically significant difference observed, in postoperative complications, such as epistaxis, rhinorrhea, postoperative nausea/vomiting, seizures, hypertension, and hypotension. When looking at the incidence of postoperative diabetes insipidus, a significant difference was found between the groups. When examining the mortality rates on the 28th day, a significant difference was found between the groups, with a mortality rate of 25% in the high TSH group (p < 0.5).

CONCLUSIONS

The risk of perioperative mortality is higher in patients with TSH levels above normal.

Evaluation of Retrospective Patient Preference on Extent of Resection of Nonfunctioning Pituitary Adenomas

BACKGROUND

Neurosurgeons treat nonfunctioning pituitary adenomas by surgical resection. Based on the adherence of the tumor to the normal pituitary gland, operative risks may include hormone replacement therapy for postoperative hypopituitarism with gross total resection that injures the gland or recurrent tumor with subtotal resection and purposeful avoidance of gland manipulation. None of the patients presented in this article had a preoperative preference regarding extent of resection. This study aimed to evaluate postoperative patient preferences regarding extent of resection.

METHODS

Adult patients who underwent resection of adenomas between 2015 and 2023 were retrospectively reviewed and surveyed. After surgery, participating patients were asked for their preference regarding 100% tumor resection with lifelong daily hormone replacement therapy versus 90% tumor resection with a chance of recurrence in the hypothetical situation where the neurosurgeon encounters tumor adherent to the normal gland.

RESULTS

Of the 73 patients included, 54 (74.0%) responded to the survey, with the majority (36 [66.7%]) preferring 90% resection with the chance of tumor recurrence. Tumor recurrence (odds ratio 2.3, 95% confidence interval 2.1-2.5, P = 0.03) and steroid avoidance (odds ratio 2.2, 95% confidence interval 2.0-2.4, P = 0.04) were the 2 variables that were significant predictors of patient preference in multivariate regression analysis.

CONCLUSIONS

Although patients may not have the preoperative insight or experience to have a strong conviction regarding the extent of adenoma resection, the consequences following surgery clearly influence their preference. Most patients in our study, including patients with gross total resection and especially patients who experienced side effects of steroid therapy, preferred subtotal resection with the chance of tumor recurrence over hormone replacement therapy.

Clinical characteristics and therapeutic outcomes of acromegalic patients with giant growth hormone-secreting pituitary adenomas: a single-center study of 67 cases

PURPOSE

Acromegalic patients with giant growth hormone-secreting pituitary adenomas (GHPAs) (≥ 40 mm) are relatively rare, and their clinical characteristics and treatment outcome data are limited. This study aims to analyze the clinical practice experience of giant GHPAs.

METHODS

Sixty-seven acromegalic patients with giant GHPAs and 67 patients with macro GHPAs (10-39 mm), matched for age and gender from the same hospital during the same period, were retrospectively recruited. The clinical characteristics, treatment, and outcomes were analyzed.

RESULTS

Enlargement of the extremities and facial features were the most common symptoms in most patients (92.5%). Compared with the macroadenoma group, more frequent visual impairment (86.6% vs. 25.4%, P < 0.001) and gonadal axis dysfunction (49.3% vs. 34.3%, P = 0.008), higher preoperative fasting GH, nadir GH after OGTT and IGF-1 levels, and a higher proportion of extrasellar tumor invasion were seen in the giant adenoma group. As the adenoma size increases, the total resection rate decreases, and postoperative complications and multimodal treatment strategies increase significantly. Fasting and nadir GH levels remained higher at 1 week postoperatively, and there were more surgical complications and cases of anterior hypopituitarism in the giant group. After a median follow-up of 36 months, 12 patients (36.4%) in the giant GHPA group and 17 (36.2%) in the macro GHPA group achieved biochemical remission. Other factors such as age of onset, age of diagnosis, delayed diagnosis time, metabolic complications, p53 positive rate, and Ki-67 index showed no significant difference between the two groups.

CONCLUSIONS

With aggressive multimodal therapy, the biochemical remission rate of acromegalic patients with giant GHPAs is comparable to that of patients with macro adenoma. However, postoperative complications and hypopituitarism need to be closely monitored.

Health Care Disparities in Transsphenoidal Surgery for Pituitary Tumors: An Experience from Neighboring Urban Public and Private Hospitals

Objectives  Few studies have assessed the role of socioeconomic health care disparities in skull base pathologies. We compared the clinical history and outcomes of pituitary tumors at private and public hospitals to delineate whether health care disparities exist in pituitary tumor surgery. Methods  We reviewed the records of patients who underwent transsphenoidal pituitary tumor resection at NYU Langone Health and Bellevue Hospital. Seventy-two consecutive patients were identified from each hospital. The primary outcome was time-to-surgery from initial recommendation. Secondary outcomes included postoperative diabetes insipidus, cerebrospinal fluid (CSF) leak, and gross total resection. Results  Of 144 patients, 23 (32%) public hospital patients and 24 (33%) private hospital patients had functional adenomas ( p  = 0.29). Mean ages for public and private hospital patients were 46.5 and 51.1 years, respectively ( p  = 0.06). Private hospital patients more often identified as white ( p  < 0.001), spoke English ( p  < 0.001), and had private insurance ( p  < 0.001). The average time-to-surgery for public and private hospital patients were 46.2 and 34.8 days, respectively ( p  = 0.39). No statistically significant differences were found in symptom duration, tumor size, reoperation, CSF leak, or postoperative length of stay; however, public hospital patients more frequently required emergency surgery ( p  = 0.03), developed transient diabetes insipidus ( p  = 0.02), and underwent subtotal resection ( p  = 0.04). Conclusion  Significant socioeconomic differences exist among patients undergoing pituitary surgery at our institution's hospitals. Public hospital patients more often required emergency surgery, developed diabetes insipidus, and underwent subtotal tumor resection. Identifying these differences is an imperative initial step in improving the care of our patients.

Update on Current Evidence for the Diagnosis and Management of Nonfunctioning Pituitary Neuroendocrine Tumors

Pituitary neuroendocrine tumors (PitNETs) are the third most frequently diagnosed intracranial tumors, with nonfunctioning PitNETs (nfPitNETs) accounting for 30% of all pituitary tumors and representing the most common type of macroPitNETs. NfPitNETs are usually benign tumors with no evidence of hormone oversecretion except for hyperprolactinemia secondary to pituitary stalk compression. Due to this, they do not typically present with clinical syndromes like acromegaly, Cushing's disease or hyperthyroidism and instead are identified incidentally on imaging or from symptoms of mass effects (headache, vision changes, apoplexy). With the lack of effective medical interventions, first-line treatment is transsphenoidal surgical resection, however, nfPitNETs often have supra- or parasellar extension, and total resection of the tumor is often not possible, resulting in residual tumor regrowth or reoccurrence. While functional PitNETs can be easily followed for recurrence using hormonal biomarkers, there is no similar parameter to predict recurrence in nfPitNETs, hence delaying early recognition and timely management. Therefore, there is a need to identify prognostic biomarkers that can be used for patient surveillance and as therapeutic targets. This review focuses on summarizing the current evidence on nfPitNETs, with a special focus on potential new biomarkers and therapeutics.

Incidental versus symptomatic nonfunctioning pituitary adenomas: Are they different?

BACKGROUND

Nonfunctioning pituitary adenomas (NFPAs) constitute one of the most common tumours in the sellar region and are often discovered only when associated with compressive symptoms. With the frequent use of brain imaging, there has been an increase in the prevalence of incidentally discovered NFPAs.

AIM

We aim to determine the prevalence of incidental diagnosis with NPAs observed over a decade and compare the analytical, clinical and treatment differences between those who were diagnosed either incidentally or symptomatically. We also intend to evaluate the pathology differences between both groups.

METHODS

We retrospectively analysed patients aged ≥18 years with an apparent NFPA, defined as a pituitary lesion compatible with pituitary adenoma which is not associated with the clinical or biochemical evidence of a hormone-secreting tumour. Inclusion criteria included normal prolactin level for lesions <9 mm or a prolactin level <100 ng/mL for lesions ≥10 mm in maximal tumour diameter.

RESULTS

We included 119 patients [53.8% males; mean age: 56.8 years (SD = 16.7)]. Diagnosis was incidental in 47.1% of patients, and many patients had unappreciated signs and symptoms of pituitary disease. In the symptomatic and incidental groups, 66.7% and 41.1% of patients had hypopituitarism, respectively (p = .005). Only 20.4% of patients incidentally diagnosed had microadenoma (p = .060). Hypopituitarism was present in 18.8% of those patients with microadenomas. Most tumours were macroadenomas (87.4%). Half of those patients diagnosed incidentally were submitted to surgery, compared with 75.8% of those who were diagnosed symptomatically (p = .004).

CONCLUSIONS

Nonfunctioning pituitary adenomas are commonly diagnosed incidentally, with many manifesting symptoms on examination. NFPAs incidentally diagnosed are more commonly macroadenomas and less frequently associated with hypopituitarism than symptomatic. Accordingly, if there was a greater level of knowledge and more suspicion about these pathologies, it might be possible to discover them earlier.

The importance of measuring prolactin prior to surgical management of a pituitary lesion: An illustrative case

The characterization of sellar and suprasellar lesions is reliant on patient presentation, medical imaging, and hormone profiling. Prolactinomas are the most common type of functional pituitary adenomas, accounting for up to 57%. Importantly, prolactinomas can present without clear symptoms and with doubtful or even normal imaging. A 41-year-old male patient was referred to neurosurgery for consideration for resection of a sellar lesion, as initial CT imaging suggested a large meningioma. Subsequent MRI of the sella favored macroadenoma, meningioma, and craniopharyngioma as the top differential considerations. These conditions all indicate a diagnosis that would require surgical management. Clinical evaluation of this patient did not elicit any obvious clinical features suggestive of hyperprolactinemia. Fortunately, we obtained a full hormone panel which revealed a significantly elevated prolactin level of 17,390 µg/L. Based on this elevated prolactin level, we diagnosed a pituitary giant prolactinoma. Treatment with a dopamine agonist therapy was initiated and the response confirmed this diagnosis. This case demonstrates the importance of obtaining a prolactin level prior to surgical management of a sellar lesion. Had a prolactin level not been obtained, this patient would have undergone surgical resection based on both the imaging and clinical judgment.

Non-functional Pituitary Adenomas: Analysis of Delayed Diagnosis in Mexico

BACKGROUND

 Although tumors of the central nervous system (CNS) are rare, they can cause significant morbidity and mortality. The clinical presentation of patients with non-functional pituitary adenomas (NFPA) ranges from being completely asymptomatic to causing pituitary, hypothalamic, or visual dysfunction due to their large size. Patients usually arrive with large tumors at the time of diagnosis.  Objectives: Try to describe the characteristics of NFPA and explain the causes of delayed diagnosis.  Methods: We carried out a retrospective study including 58 patients with NFPA and analyzed the tumor volume at the time of diagnosis and its relationship with sociodemographic and health sector variables.  Results: Low socioeconomic status (SES) was associated with high tumor volume (SES 1-2 of 17.4 cm3 vs 3-6 of 11.7 cm3, p=0.018), and the time between first consultation and diagnosis was longer in the public sector than in the private sector (13.5 months vs 5.1 months). The time between the first symptom and the first consultation was shorter when they had visual impairment than when they did not (4.1 vs 18.4 months, p=0.006).

CONCLUSIONS

On the one hand, citizens should be made aware that a visual deficit should make them go to a medical check-up, and on the other hand, strengthen the health system so that they have the NFPA as a differential diagnosis in patients with some visual alteration. Socioeconomic inequality in our country undoubtedly puts the underprivileged at greater risk.

A Novel Magnetic Resonance Imaging-Based Radiomics and Clinical Predictive Model for the Regrowth of Postoperative Residual Tumor in Non-Functioning Pituitary Neuroendocrine Tumor

Background and Objectives: To develop a novel magnetic resonance imaging (MRI)-based radiomics-clinical risk stratification model to predict the regrowth of postoperative residual tumors in patients with non-functioning pituitary neuroendocrine tumors (NF-PitNETs). Materials and Methods: We retrospectively enrolled 114 patients diagnosed as NF-PitNET with postoperative residual tumors after the first operation, and the diameter of the tumors was greater than 10 mm. Univariate and multivariate analyses were conducted to identify independent clinical risk factors. We identified the optimal sequence to generate an appropriate radiomic score (Rscore) that combined pre- and postoperative radiomic features. Three models were established by logistic regression analysis that combined clinical risk factors and radiomic features (Model 1), single clinical risk factors (Model 2) and single radiomic features (Model 3). The models' predictive performances were evaluated using receiver operator characteristic (ROC) curve analysis and area under curve (AUC) values. A nomogram was developed and evaluated using decision curve analysis. Results: Knosp classification and preoperative tumor volume doubling time (TVDT) were high-risk factors (p < 0.05) with odds ratios (ORs) of 2.255 and 0.173. T1WI&T1CE had a higher AUC value (0.954) and generated an Rscore. Ultimately, the AUC of Model 1 {0.929 [95% Confidence interval (CI), 0.865-0.993]} was superior to Model 2 [0.811 (95% CI, 0.704-0.918)] and Model 3 [0.844 (95% CI, 0.748-0.941)] in the training set, which were 0.882 (95% CI, 0.735-1.000), 0.834 (95% CI, 0.676-0.992) and 0.763 (95% CI, 0.569-0.958) in the test set, respectively. Conclusions: We trained a novel radiomics-clinical predictive model for identifying patients with NF-PitNETs at increased risk of postoperative residual tumor regrowth. This model may help optimize individualized and stratified clinical treatment decisions.

Identification of biomarkers associated with the invasion of nonfunctional pituitary neuroendocrine tumors based on the immune microenvironment

Introduction

The invasive behavior of nonfunctioning pituitary neuroendocrine tumors (NF-PitNEts) affects complete resection and indicates a poor prognosis. Cancer immunotherapy has been experimentally used for the treatment of many tumors, including pituitary tumors. The current study aimed to screen the key immune-related genes in NF-PitNEts with invasion.

Methods

We used two cohorts to explore novel biomarkers in NF-PitNEts. The immune infiltration-associated differentially expressed genes (DEGs) were obtained based on high/low immune scores, which were calculated through the ESTIMATE algorithm. The abundance of immune cells was predicted using the ImmuCellAI database. WGCNA was used to construct a coexpression network of immune cell-related genes. Random forest analysis was used to select the candidate genes associated with invasion. The expression of key genes was verified in external validation set using quantitative real-time polymerase chain reaction (qRT‒PCR).

Results

The immune and invasion related DEGs was obtained based on the first dataset of NF-PitNEts (n=112). The immune cell-associated modules in NF-PitNEts were calculate by WGCNA. Random forest analysis was performed on 81 common genes intersected by immune-related genes, invasion-related genes, and module genes. Then, 20 of these genes with the highest RF score were selected to construct the invasion and immune-associated classification model. We found that this model had high prediction accuracy for tumor invasion, which had the largest area under the receiver operating characteristic curve (AUC) value in the training dataset from the first dataset (n=78), the self-test dataset from the first dataset (n=34), and the independent test dataset (n=73) (AUC=0.732/0.653/0.619). Functional enrichment analysis revealed that 8 out of the 20 genes were enriched in multiple signaling pathways. Subsequently, the 8-gene (BMP6, CIB2, FABP5, HOMER2, MAML3, NIN, PRKG2 and SIDT2) classification model was constructed and showed good efficiency in the first dataset (AUC=0.671). In addition, the expression levels of these 8 genes were verified by qRT‒PCR.

Conclusion

We identified eight key genes associated with invasion and immunity in NF-PitNEts that may play a fundamental role in invasive progression and may provide novel potential immunotherapy targets for NF-PitNEts.

Pediatric diencephalic tumors: a constellation of entities and management modalities

The diencephalon is a complex midline structure consisting of the hypothalamus, neurohypophysis, subthalamus, thalamus, epithalamus, and pineal body. Tumors arising from each of these diencephalic components differ significantly in terms of biology and prognosis. The aim of this comprehensive review is to describe the epidemiology, clinical symptoms, imaging, histology, and molecular markers in the context of the 2021 WHO classification of central nervous system neoplasms. We will also discuss the current management of each of these tumors.

The Party Wall: Redefining the Indications of Transcranial Approaches for Giant Pituitary Adenomas in Endoscopic Era

The evolution of endoscopic trans-sphenoidal surgery raises the question of the role of transcranial surgery for pituitary tumors, particularly with the effectiveness of adjunct irradiation. This narrative review aims to redefine the current indications for the transcranial approaches for giant pituitary adenomas in the endoscopic era. A critical appraisal of the personal series of the senior author (O.A.-M.) was performed to characterize the patient factors and the tumor's pathological anatomy features that endorse a cranial approach. Traditional indications for transcranial approaches include the absent pneumatization of the sphenoid sinus; kissing/ectatic internal carotid arteries; reduced dimensions of the sella; lateral invasion of the cavernous sinus lateral to the carotid artery; dumbbell-shaped tumors caused by severe diaphragm constriction; fibrous/calcified tumor consistency; wide supra-, para-, and retrosellar extension; arterial encasement; brain invasion; coexisting cerebral aneurysms; and separate coexisting pathologies of the sphenoid sinus, especially infections. Residual/recurrent tumors and postoperative pituitary apoplexy after trans-sphenoidal surgery require individualized considerations. Transcranial approaches still have a critical role in giant and complex pituitary adenomas with wide intracranial extension, brain parenchymal involvement, and the encasement of neurovascular structures.

Epigenomic and transcriptomic landscaping unraveled candidate repositioned therapeutics for non-functioning pituitary neuroendocrine tumors

PURPOSE

Non-functioning pituitary neuroendocrine tumors are challengingly diagnosed tumors in the clinic. Transsphenoidal surgery remains the first-line treatment. Despite the development of state-of-the-art techniques, no drug therapy is currently approved for the treatment. There are also no randomized controlled trials comparing therapeutic strategies or drug therapy for the management after surgery. Therefore, novel therapeutic interventions for the therapeutically challenging NF-PitNETs are urgently needed.

METHODS

We integrated epigenome and transcriptome data (both coding and non-coding) that elucidate disease-specific signatures, in addition to biological and pharmacological data, to utilize rational pathway and drug prioritization in NF-PitNETs. We constructed an epigenome- and transcriptome-based PPI network and proposed hub genes. The signature-based drug repositioning based on the integration of multi-omics data was performed.

RESULTS

The construction of a disease-specific network based on three different biological levels revealed DCC, DLG5, ETS2, FOXO1, HBP1, HMGA2, PCGF3, PSME4, RBPMS, RREB1, SMAD1, SOCS1, SOX2, YAP1, ZFHX3 as hub proteins. Signature-based drug repositioning using hub proteins yielded repositioned drug candidates that were confirmed in silico via molecular docking. As a result of molecular docking simulations, palbociclib, linifanib, trametinib, eplerenone, niguldipine, and zuclopenthixol showed higher binding affinities with hub genes compared to their inhibitors and were proposed as potential repositioned therapeutics for the management of NF-PitNETs.

CONCLUSION

The proposed systems' biomedicine-oriented multi-omics data integration for drug repurposing to provide promising results for the construction of effective clinical therapeutics. To the best of our knowledge, this is the first study reporting epigenome- and transcriptome-based drug repositioning for NF-PitNETs using in silico confirmations.

The effect of endoscopic transsphenoidal somatotroph tumors resection on pituitary hormones: systematic review and meta-analysis

PURPOSE

Currently, endoscopic transsphenoidal surgery is the main treatment for pituitary neuroendocrine tumors (PitNETs). Excision of the tumor may have positive or negative effects on pituitary endocrine function, and the pituitary function of somatotroph tumors is a point of particular concern after the operation. This study aimed to conduct a meta-analysis on the effect of endoscopic transsphenoidal somatotroph tumor resection on pituitary function.

METHODS

A systematic literature search was conducted for articles that included the evaluation of pituitary target gland before and after endoscopic transsphenoidal pituitary tumor resection and were published between 1992 and 2022 in PubMed, Cochrane, and Ovid MEDLINE.

RESULTS

Sixty-eight studies that included biochemical remission rates in 4524 somatotroph tumors were concluded. According to the 2000 consensus, the biochemical remission rate after transsphenoidal endoscopic surgery was 66.4% (95% CI, 0.622-0.703; P = 0.000), the biochemical remission rate was 56.2% according to the 2010 consensus (95% CI, 0.503-0.620; P = 0.041), and with the rate of biochemical remission ranging from 30.0 to 91.7% with investigator's definition. After endoscopic resection, adrenal axis dysfunction was slightly higher than that before surgery, but the difference was not statistically significant. Hypothyroidism was 0.712 times higher risk than that before surgery (OR = 0.712; 95% CI, 0.527-0.961; P = 0.027). Hypogonadism was 0.541 times higher risk than that before surgery (OR = 0.541; 95% CI, 0.393-0.746; P = 0.000). Hyperprolactinemia was 0.131 times higher risk than that before surgery (OR = 0.131; 95% CI, 0.022-0.783; P = 0.026). The incidence of pituitary insufficiency was 1.344 times the risk before surgery after endoscopic resection of somatotroph tumors, but the difference was not statistically significant.

CONCLUSIONS

In patients with somatotroph tumors after undergoing endoscopic surgery, the risk of dysfunction and pituitary insufficiency tend to increase, while preoperative thyroid insufficiency, gonadal insufficiency, and hyperprolactinemia will be partially relieved.

Clinical characteristics and outcome in 15 dogs treated with transsphenoidal hypophysectomy for nonfunctional sellar masses

OBJECTIVE

To characterize the clinical features, neurological examination findings, diagnostic imaging results, histopathological findings, and outcome following transsphenoidal hypophysectomy (TSH) in dogs with nonfunctional sellar masses (NFSM).

STUDY DESIGN

Multi-institutional retrospective study.

METHODS

Medical records of dogs that underwent TSH for a NFSM were reviewed for clinical signs, physical and neurological examination findings, diagnostic imaging results, endocrine testing, surgery reports, and outcome. Magnetic resonance (MR) imaging was rereviewed, and tumors were classified using the previously described system according to pituitary tumor extension and vascular involvement. Owners of dogs that survived to discharge were contacted.

RESULTS

The majority of dogs presented for mentation change (12/15). The mean pituitary to brain ratio (P/B ratio) was 1.05 (0.6-1.4). Eight dogs had a tumor imaging classification of 5B. Eleven dogs were diagnosed with a nonfunctional pituitary adenoma (NFPA). Perioperative mortality was 33% (5/15). The median survival for all dogs was 232 days (0-1658). When dogs that did not survive to discharge were excluded, the median survival time was 708 days. Seven of 10 dogs that survived the perioperative period received adjunctive therapy. Owner assessment of outcome was excellent (6/7) to good (1/7).

CONCLUSION

The common presenting complaint for dogs with large NFSM causing mass effect was mentation changes. Dogs with NFPA that survived to discharge and received adjunctive therapy had good to excellent outcomes.

CLINICAL SIGNIFICANCE

Transsphenoidal debulking with adjunctive therapy can be considered for the treatment of NFSM causing clinical signs of mass effect in dogs. Successful long-term outcomes are possible.

The outcomes of surgical treatment via transsphenoidal approach for patients with nonfunctioning pituitary adenoma: a single institution's experience

BACKGROUND

Nonfunctioning pituitary adenoma is a primary benign brain neoplasm and the transsphenoidal approach is known for a safe and effective first-line surgical treatment for pituitary tumours. The aim of this study was to retrospectively analyse the outcomes of the transsphenoidal approach for nonfunctioning pituitary adenomas treated at a single institute.

METHODS

A total of 181 patients who underwent transsphenoidal approach with nonfunctioning pituitary adenoma at a single institute from March 1998 to November 2018 were included in this study. Ninety-six (53.0%) men and 85 (47.0%) women aged 21-79 years were included. The median outpatient follow-up duration was 58 months, and the median magnetic resonance imaging follow-up duration was 54 months. We assessed the surgical and clinical outcomes, complications, hormonal outcomes and recurrence tendency.

RESULTS

The overall total resection rate of a transsphenoidal approach for nonfunctioning pituitary adenoma was 84.0%. Visual impairment was improved after surgery in 115 (93.5%) of 123 patients. Of the 80 patients who complained of preoperative endocrine dysfunction, 62 (77.5%) patients recovered normal postoperative endocrine function. Diabetes insipidus, which occurred in 22 (12.2%) patients, was the most common complication. A total of 21 (11.6%) patients showed recurrence on average 57.6 months after surgery. The average recurrence period after surgery was 96.3 months in the total resection group of 6 patients and 42.1 months in the subtotal resection group of 15 patients. In multivariate analysis, the extent of resection was identified as a significant predictor of tumour recurrence with a hazard ratio of 6.093 and a p-value of 0.002.

CONCLUSIONS

It is meaningful to report long-term surgical results within a single institution, and through this, it was reconfirmed that transsphenoidal approach is an effective and safe treatment for nonfunctioning pituitary adenoma. Long-term follow-up is required due to the possibility of recurrence. In addition, performing total resection during surgery helps to lower the risk of recurrence.KEY MESSAGESTranssphenoidal approach is an effective and safe treatment modality for pituitary adenoma.Complete resection is a significant predictor for the recurrence of pituitary adenomaLong-term follow-up is necessary for the treatment of nonfunctioning pituitary adenomas.

Current medical treatment and perspective in gonadotroph tumors

Gonadotroph cell adenoma is the most common clinically nonfunctioning pituitary adenoma; and is pathologically defined by immunopositivity for SF-1, GATA2 and ER-α. Most tumors also stain for follicle stimulating hormone and luteinizing hormone β-subunits, but are usually hormonally silent and discovered incidentally or due to local mass effects. Complete transsphenoidal resection should be attempted when surgery is indicated. Post-surgical treatment can include radiation of the tumor remnant and medical treatment. Among medical treatments, dopamine agonists show the best evidence for preventing the need for recurrent surgery or radiation, and should be considered in patients with relatively bulky remnants or who have high risk features associated with tumor progression. Temozolomide is indicated for aggressive adenomas and carcinomas. Less well-established treatments include somatostatin receptor ligands, peptide receptor radionucleotide therapy and immunomodulatory agents.

Risk factors for delayed postoperative hyponatremia in patients with non-functioning pituitary adenomas undergoing transsphenoidal surgery: A single-institution study

Purpose

We aimed to assess factors influencing the occurrence of delayed hyponatremia after transsphenoidal surgery (TSS) in patients with a non-functional pituitary adenoma (NFPA).

Methods

We retrospectively collected the clinical data of patients who underwent TSS for NFPA between January 2016 and January 2021. The pituitary region was preoperatively scanned with 3.0 T magnetic resonance imaging. The risk factors for delayed postoperative hyponatremia for NFPA were identified by univariate and multivariable logistic regression analysis.

Results

We selected 166 patients with NFPA who fulfilled the inclusion criteria. Delayed postoperative hyponatremia occurred in 28 patients and did not in 138. Multivariable logistic regression analyses demonstrated that higher odds of developing delayed postoperative hyponatremia were independently associated with larger craniocaudal dimension (OR = 1.128, P = 0.034), as well as preoperative hyperprolactinemia (OR = 2.618, P = 0.045) and larger preoperative pituitary stalk deviation angle (OR = 3.033, P = 0.022).

Conclusion

We identified the independent risk factors for delayed hyponatremia after TSS for NFPA; these included preoperative hyperprolactinemia, craniocaudal diameter, and preoperative pituitary stalk deviation angle.

Silent Corticotroph and Somatotroph Double Pituitary Adenoma: A Case Report and Review of Literature

Clinically silent double pituitary adenomas consisting of corticotroph and somatotroph cells are an exceedingly rare clinical finding. In this report, we present the case of a 28-year-old man with a 1-year history of recurrent headaches. Imaging revealed a 2.1 (anterior-posterior) × 2.2 (transverse) × 1.3 (craniocaudal) cm pituitary adenoma invading into the left cavernous sinus and encasing the left internal carotid artery. Endoscopic transnasal resection was performed without complications. Immunohistochemical staining revealed a double adenoma consisting of distinct sparsely granulated somatotroph and densely granulated corticotroph cells that were positive for growth hormone and adrenocorticotropic hormone, respectively. K _i -67 index labeling revealed a level of 6% within the corticotroph adenoma. No increase in serum growth hormone or adrenocorticotropic hormone was found, indicating a clinically silent double adenoma. While transsphenoidal surgery remains a first-line approach for silent adenomas presenting with mass effects, increased rates of proliferative markers, such as the K _i -67 index, provide useful insight into the clinical course of such tumors. Determining the K _i -67 index of silent pituitary adenomas could be valuable in predicting recurrence after initial surgical resection and identifying tumors that are at an increased risk of needing additional therapeutic interventions or more frequent surveillance imaging.

Sinonasal Symptoms and Self-Reported Health before and after Endoscopic Pituitary Surgery—A Prospective Study

Objectives Despite the limited invasiveness of endoscopic transsphenoidal surgery (ETSS), some degree of nasal structure destruction is unavoidable. Our objective was to evaluate sinonasal morbidity and self-reported health before and 6 months after ETSS for pituitary tumors, and to identify possible predictive factors for deterioration in sinonasal health.

Design Prospective observational cohort study.

Setting University tertiary referral hospital.

Participants Totally 109 consecutive adult patients undergoing ETSS for pituitary tumors between 2015 and 2019.

Main Outcome Measures Sinonasal symptoms and self-reported health before and 6 months after ETSS, assessed by the Sinonasal Outcome Test (SNOT-22) and the EQ-5D questionnaire. Predictive factors for postoperative deterioration in sinonasal symptoms.

Results The overall SNOT-22 score did not change, but the score of the rhinologic domain of SNOT-22 worsened from 6.0 ± 5.9 before to 8.0 ± 7.4 6 months after surgery (p = 0.011). The EQ-5D visual analog scale improved from 64.0 ± 22.9 before to 71.1 ± 18.7 6 months after surgery (p = 0.00088). Univariate and multivariable regression analyses showed that prior sinonasal surgery was associated with a significant worsening in rhinologic symptoms 6 months after surgery (p = 0.046 and p = 0.020, respectively).

Conclusions Although self-reported overall health improved, significant deterioration of rhinologic symptoms was seen 6 months after ETSS. This information is important for preoperative patient counselling. Further refinement of the surgical technique and follow-up strategies to reduce postoperative sinonasal morbidity could be of value, especially in patients who have undergone prior sinonasal surgery.

Radiological evolution of autograft fat used for skull base reconstruction after transsphenoidal surgery for pituitary adenomas

PURPOSE

Cerebro-spinal fluid leak after transsphenoidal surgery for pituitary adenomas may be prevented by skull base reconstruction with fat autograft. However, graft changes may interfere with the interpretation of postoperative images. Our aim is to describe the radiological evolution of the fat autograft.

METHODS

A retrospective analysis was performed, including patients undergoing a transsphenoidal surgery for pituitary adenomas with a fat autograft for skull base reconstruction. Clinical and radiological data were collected, with assessment of fat autograft and extent of resection. Statistical analysis was performed using Kruskal-Wallis and Wilcoxon signed-rank test while Spearman's Rho was used to analyze the relationship between variables.

RESULTS

Seventy-two patients were included. Macroadenomas were diagnosed in 62 cases (86.1%) and in 21 cases an invasion of the cavernous sinus was described (29%). Gross total resection was achieved in 84.7% of cases. The volume of the fat graft significantly decreased between 3 months and 1 year after surgery (p = 0.01) and between 1 year and the last follow-up (mean 4.63 years, p < 0.01). Fat signal ratio significantly diminished between 3 months and 1 year in unenhanced and enhanced T1-weighted sequences (p = 0.04 and p = 0.02 respectively). Volume reduction was related to the decrease in signal ratio in unenhanced T1 sequences (p = 0.008).

CONCLUSION

Fat resorbs with time: almost 50% of the fat volume is lost during the first year after surgery and 60% is resorbed at 4.6 years. T1-signal, before and after gadolinium injection, also decreases during the first year, probably because of the progressive fibrosis of the graft. This information will contribute to the interpretation of postoperative images.

Microwaves as Diagnostic Tool for Pituitary Tumors: Preliminary Investigations

To date, tumors, the second cause of death worldwide, are a modern medicine plight. The development of rapid, cost-effective and reliable prevention and diagnostics tools is mandatory to support clinicians and ensure patients’ adequate intervention. Pituitary tumors are a class of neoplasm, which calls for suitable and ad hoc diagnostic tools. Recently, microwaves have gained interest as a non-ionizing, non-invasive valuable diagnostic approach for identifying pathologic tissues according to their dielectric properties. This work deals with the preliminary investigation of the feasibility of using microwaves to diagnose pituitary tumors. In particular, it focuses on benign tumors of the adenohypophysis, e.g., the pituitary adenomas. It is assumed to access the region of interest of the pituitary region by following a trans-sphenoidal approach. The problem was modeled by developing an equivalent transmission line model of the multi-layered, lossy tissues (front bone of sphenoid sinuses, air in the sinuses, posterior bone of sphenoid sinuses, the pituitary gland and the tumor). The forward problem was developed to investigate the transmission coefficient for identifying the most favorable propagation conditions. Then, it was analyzed if, by the solution of an inverse problem, it is possible to reconstruct the permittivity and electrical conductivity profiles and identify the tumor presence. The results are promising since a maximum reconstruction error of 8% is found, in the worst case, thus paving the way for the use of microwaves for the diagnosis of pituitary tumors.

Carotid artery injury in endoscopic endonasal surgery: Risk factors, prevention, and management

Objective

Endoscopic approaches for sinus and skull base surgery are increasing in popularity. The objective of this narrative review is to characterize risk factors for internal carotid artery injury in endoscopic endonasal surgery (EES), highlight preventative measures, and illustrate key management principles.

Data Sources

Comprehensive literature review.

Methods

Relevant literature was reviewed using PubMed/MEDLINE.

Results

Carotid artery injury in EES is rare, with most studies reporting an incidence below 0.1%. Anatomic aberrancies, wide dissection margins, as well as specific provider and hospital factors, may increase the risk of injury. Multidisciplinary teams, comprehensive preoperative imaging, patient risk assessment, and formal training in vascular emergencies may reduce the risk. Management protocols should emphasize proper visualization of the injury site, fluid replacement, rapid packing, angiography, and endovascular techniques to achieve hemostasis.

Conclusions

While EES is a relatively safe procedure, carotid artery injury is a devastating complication that warrants full consideration in surgical planning. Important preventative measures include identifying patients with notable risk factors and obtaining preoperative imaging. Multidisciplinary teams and management protocols are ultimately necessary to reduce morbidity and mortality.

Internal carotid artery (ICA) injury is a rare complication of endoscopic endonasal surgery.

Risk factors for ICA injury may include vascular anatomic variants, invasive pathology, and prior radiation therapy.

Surgical team preparation and experience are key to successful management of operative complications.

Outcome of Endoscopic Transsphenoidal Surgery for Recurrent or Residual Pituitary Adenomas and Comparison to Non-Recurrent or Residual Cohort by Propensity Score Analysis

OBJECTIVE

To evaluate the long-term outcomes and safety of endoscopic transsphenoidal surgery (ETS) in recurrent and residual pituitary adenomas (rrPAs), as well as the predictors of gross total resection (GTR) and intraoperative CSF leakage. Furthermore, to compare outcomes and complications with non-rrPAs cohort.

METHODS

Clinical and radiological characteristics of patients with rrPAs who underwent ETS were collected between 2017 and 2020. Data of patients with non-rrPAs were collected from 2019 to 2020. Logistic regression analyses were performed to investigate the factors influencing gross total resection (GTR) and intraoperative CSF leakage. Between-group comparisons of outcomes and complications were performed through propensity score analysis.

RESULTS

We enrolled 73 patients with rrPAs. GTR was achieved in 41 (56.1%) cases; further, GTR or near-total resection was achieved in 93.2% of patients. The mean tumor volumes for GTR and non-GTR cases were 6.2 ±7.2 cm³ and 11.1 ±9.1 cm³, respectively. Multivariate regression analysis of the GTR rate in patients with rrPAs revealed that Knosp grade was an independent factor (odds ratio [OR] = 0.324; p=0.005). Moreover, previous transcranial surgery and non-functional pituitary adenomas were risk factors for intraoperative CSF leakage in patients with rrPAs (OR=6.450, p=0.019 and OR=7.472, p=0.012, respectively). After propensity score matching, There was no significant difference in the GTR rate between patients with rrPAs and patients with non-rrPAs. Contrastingly, patients with rrPAs had a higher rate of intraoperative CSF leakage and longer postoperative hospital stay than patients with non-rrPAs. During the follow-up, vision improved in 9 (22.0%) and 24 (62.5%) patients with rrPAs and non-rrPAs, respectively. Although there was a trend that reoperation of rrPAs involved a lower hypopituitarism recovery rate and biochemical remission rate, as well as a higher hypopituitarism rate, there was no statistically significant between-group difference.

CONCLUSIONS

Knosp grade was an independent factor for GTR in endoscopic transsphenoidal surgery in patients with rrPAs. Previous transcranial surgery and non-functional PAs were risk factors for intraoperative CSF leakage. Although associated with longer hospital stay, rrPAs did not associate with lower GTR rate or more frequent postoperative complications than non-rrPAs cohort.

Endocrine Function after Transsphenoidal Surgery in Patients with Non-Functioning Pituitary Adenomas: A Systematic Review and Meta-Analysis

INTRODUCTION

Transsphenoidal surgery is the current treatment for mass reduction in patients with non-functional pituitary adenomas (NFPAs). The surgical procedure may deteriorate or recover pituitary endocrine function. The aim of this study was to systematically assess the benefits and harms of transsphenoidal surgery on pituitary endocrine function in patients with NFPAs.

METHODS

This systematic review and meta-analysis was registered with PROSPERO (registration No. CRD42020210853). We searched Pubmed and EMBASE for studies reporting on pituitary function before and after transsphenoidal surgery in patients with NFPAs having a minimum follow-up of 1 month. The prespecified primary outcomes were the proportions of patients with improved or deteriorated pituitary function after surgery reported as weighted mean using random effects meta-analysis or in case of considerable heterogeneity, i.e., I2 ≥ 75%, as a range of reported proportions. Subgroup analyses were planned for the primary outcomes on study level.

RESULTS

Of the 6,597 identified records, 24 studies enrolling 3,816 participants were eligible for assessment. Twenty-three studies were judged to have serious or critical risk of bias. The range of proportions of patients with recovery of at least one pituitary axis was between 10.2% and 97.7% (I2 = 93%), while the range of proportions of patients experiencing loss of at least one axis after pituitary surgery was between 0.0% and 36.6% (I2 = 91%). None of the a priori planned subgroup analyses explained the observed heterogeneity associated with deterioration of pituitary function after surgery, and the proportion of patients may be underestimated due to publication bias.

CONCLUSIONS

The current systematic review finds that the endocrine effect of pituitary surgery is unclear both in terms of the chance of recovery and in terms of the risk of pituitary failure and hypopituitarism should be considered only a relative indication for surgery. However, the range of effects does include potentially clinically relevant rates of pituitary recovery calling for more systematic collection of data in future studies.

Current opinion on the diagnosis and management of non-functioning pituitary adenomas

INTRODUCTION

Non-functioning pituitary adenomas (NFPAs) are clinically silent tumors and the second most common pituitary adenoma. Surgery is the mainstay of treatment as there is, as yet, no effective medical treatment.

AREAS COVERED

We present current knowledge on the clinical diagnosis, histopathological classification, molecular data, and management strategies in NFPA.

EXPERT OPINION

NFPA is a heterogeneous group of tumors, in respect to their origin and clinical course. In recent years, research on pathology and molecular biology have advanced our knowledge of NFPA pathogenesis. NFPA exhibit, in the majority of cases, an indolent behavior, with satisfactory response to treatment. In aggressive cases, multimodal management is needed; however, even this approach may be insufficient, so the development of new treatments is warranted for better management. In this setting, the understanding of the mechanisms involved in the genesis and progression of NFPA is crucial for the identification and development of directed treatments with higher chances of response.

Tumor volume improves preoperative differentiation of prolactinomas and nonfunctioning pituitary adenomas

PURPOSE

Both prolactinomas and nonfunctioning adenomas (NFAs) can present with hyperprolactinemia. Distinguishing them is critical because prolactinomas are effectively managed with dopamine agonists, whereas compressive NFAs are treated surgically. Current guidelines rely only on serum prolactin (PRL) levels, which are neither sensitive nor specific enough. Recent studies suggest that accounting for tumor volume may improve diagnosis. The objective of this study is to investigate the diagnostic utility of PRL, tumor volume, and imaging features in differentiating prolactinoma and NFA.

METHODS

Adult patients with pathologically confirmed prolactinoma (n = 21) or NFA with hyperprolactinemia (n = 58) between 2013 and 2020 were retrospectively identified. Diagnostic performance of clinical and imaging variables was analyzed using receiver-operating characteristic curves to calculate area under the curve (AUC).

RESULTS

Tumor volume and PRL positively correlated for prolactinoma (r = 0.4839, p = 0.0263) but not for NFA (r = 0.0421, p = 0.7536). PRL distinguished prolactinomas from NFAs with an AUC of 0.8892 (p < 0.0001) and optimal cut-off value of 62.45 ng/ml, yielding a sensitivity of 85.71% and specificity of 94.83%. The ratio of PRL to tumor volume had an AUC of 0.9647 (p < 0.0001) and optimal cut-off value of 21.62 (ng/ml)/cm³ with sensitivity of 100% and specificity of 82.76%. Binary logistic regression found that PRL was a significant positive predictor of prolactinoma diagnosis, whereas tumor volume, presence of cavernous sinus invasion, and T2 hyperintensity were significant negative predictors. The regression model had an AUC of 0.9915 (p < 0.0001).

CONCLUSIONS

Consideration of tumor volume improves differentiation between prolactinomas and NFAs, which in turn leads to effective management.

Virtual magnetic resonance elastography has the feasibility to evaluate preoperative pituitary adenoma consistency

PURPOSE

To evaluate the use of preoperative virtual Magnetic Resonance Elastography (vMRE) for patients undergoing transsphenoidal resection of pituitary adenomas (PA).

METHODS

Ten patients (60.2 ± 19.6 years; 8 males) were prospectively examined with the vMRE-method prior to transsphenoidal surgery. vMRE-images, reflecting tissue stiffness were reconstructed. From these images, histograms as well as the mean stiffness values over the tumor body were extracted. Finally, vMRE-data was compared with the PA consistency at surgery blinded to vMRE.

RESULTS

In all patients, successful vMRE-examination was performed enabling evaluation of even small PAs. For tumors with homogenous tissue, the mean stiffness value increased with surgical consistency grading. For heterogenous tumors, however, the mean stiffness value did not consistently reflect the grading at surgery. On the other hand, the vMRE-images and histograms were found to be able to characterize the tumor heterogeneity and display focal regions of high stiffness that were found to affect the surgery outcome in these PAs. The vMRE-images and histograms showed great promise in characterizing the consistency at surgery for these PAs.

CONCLUSION

Evaluation of PA consistency in preparation for surgery seems to be feasible using the vMRE-method. Our findings also address the need for high resolution diagnostic methods that can non-invasively display focal regions of increased stiffness, as such regions may increase the difficulty of transsphenoidal PA-resection.

Outcome of pituitary hormone deficits after surgical treatment of nonfunctioning pituitary macroadenomas

OBJECTIVES

Nonfunctionning pituitary macroadenomas (NFPMA) are benign tumors that cause symptoms of mass effects including hypopituitarism. Their primary treatment is transsphenoidal surgery. We aimed to determine the outcome of pituitary hormone deficits after surgical treatment of NFPMA and to identify factors predicting hormonal recovery.

DESIGN

We retrospectively included 246 patients with NFPMA diagnosed and operated in one of the two participating centers. All hormonal axes were evaluated except growth hormone (GH). Postoperative improvement of pituitary endocrine function was considered if at least one hormonal deficit had recovered and a lower total number of deficits was observed 1 year after surgery.

RESULTS

80% (n = 197) of patients had one or more pituitary deficits and 28% had complete anterior hypopituitarism. Besides GH, the gonadotropic and thyrotropic axes were the most commonly affected (68% and 62%, respectively). The number of hypopituitary patients dropped significantly to 61% at 1 year (p < 0.001) and a significant improvement was observed for all hormonal axes, except central diabetes insipidus. Among patients with preoperative hypopituitarism, 88/175 (50%) showed improved pituitary function at 1 year. Both hyperprolactinemia at diagnosis and a lower tumor diameter independently predicted favorable endocrine outcome.

CONCLUSIONS

Hypopituitarism is present in 80% of patients with NFPMA and nearly half of them will benefit from sustained improvement after surgery. Hyperprolactinaemia at diagnosis and lower tumor dimensions are associated with favorable endocrine prognosis. This supports the option of early surgery in NFPMA patients with pituitary deficits independent of the presence of visual disturbances.

Post-operative volumes following endoscopic surgery for non-functioning pituitary macroadenomas are predictive of further intervention, but not endocrine outcomes

BACKGROUND

Transsphenoidal surgery (TSS) remains the treatment of choice for non-functioning pituitary macroadenomas (NFPMA). The value of measuring tumour volumes before and after surgery, and its influence on endocrine outcomes and further treatment of the residual or recurrent tumour are unknown.

METHODS

Data from patients who underwent endoscopic TSS for a NFPMA (2009-2018) in a UK tertiary centre were analysed for pre- and post-operative endocrine and surgical outcomes.

RESULTS

Of 173 patients with NFPMA, 159 (61% male) were treatment naïve. At presentation, 76.2% (77/101) had ≥1 pituitary axis deficit. Older age (p = 0.002) was an independent predictor for multiple hormonal deficiencies. Preoperative tumour volume did not correlate with degree of hypopituitarism. Postoperative tumour volume and extent of tumour resection were not predictive of new onset hypopituitarism. Hormonal recovery was observed in 16 patients (20.8%) with impaired pituitary function, with the greatest recovery in the hypothalamic-pituitary-adrenal axis (21.2%, 7/33). A larger residual tumour volume was predictive of adjuvant radiotherapy (3.40 vs. 1.24 cm³, p = 0.005) and likelihood for repeat surgery (5.40 vs. 1.67cm³, p = 0.004).

CONCLUSION

Pre- and post-operative NFPMA volumes fail to predict the number of pituitary hormone deficits, however, greater post-operative residual volumes increase the likelihood of further intervention to control tumour growth.

Utility of intraoperative ultrasonography for resection of pituitary adenomas: a comparative retrospective study

BACKGROUND

The evolution of pituitary surgery has made it a safe and effective form of treatment; however, risks of inadequate tumor resection, cerebrospinal fluid (CSF) leak, pituitary dysfunction, and vascular injury still exist. The use of intraoperative ultrasonography (IOUS) in pituitary surgery has been well described. Recent advancements in ultrasound technology have allowed for expanded utility as described here.

METHODS

A retrospective review was performed between January 2016 and December 2019. One hundred thirty-eight patients (mean age 53.7 years, 47% females) were identified undergoing transsphenoidal surgery for pituitary tumors. Thirty-four patients had IOUS performed using a side-firing ultrasound probe, while 104 did not. Data was analyzed for preoperative (demographics, clinical, and radiographic features), perioperative (blood loss, operative time), and postoperative (complications, length of stay, hormone remission, and extent of resection) outcomes.

RESULTS

There were no significant differences in patient age, gender, tumor volume, Knosp grade, and hormone-secreting status between the two groups. Patients treated using IOUS had significantly higher rates of gross total resection (79% vs. 44%, p = 0.0008), shorter operative times (74 vs. 146 min, p < 0.0001), lower blood loss (119 vs. 284 cc, p < 0.0001), and hospital stays (2.9 vs. 4.2 days, p = 0.001). Overall complication rates were lower in the IOUS group compared to standard pituitary surgery but did not reach significance.

CONCLUSIONS

Recent improvements in ultrasound technology have allowed for miniaturization of probes capable of delivering high-resolution images. The use of IOUS in transsphenoidal pituitary surgery may significantly increase rates of gross total resection, while decreasing blood loss, hospital LOS, and operative time.

Circulating brain injury biomarkers increase after endoscopic surgery for pituitary tumors

Pituitary tumors and subsequent treatment with endoscopic transsphenoidal surgery (ETSS) may cause injury to suprasellar structures, causing long-term fatigue and neurocognitive impairment. A method to quantify brain injury after ETSS is not available. In this prospective, exploratory study of patients undergoing ETSS for pituitary tumors, a novel approach to detect possible neuronal damage is presented. Plasma concentrations of brain injury biomarkers (glial fibrillary acidic protein [GFAP], tau, and neurofilament light [NFL]) were measured the day before surgery, immediately after surgery, at day 1 and 5, and at 6 and 12 months after surgery, using enzyme-linked immunosorbent assays. The association between the increase of biomarkers with preoperative tumor extension and postoperative patient-perceived fatigue was evaluated. Suprasellar tumor extension was assessed from MRI scans, and self-perceived fatigue was assessed using the Multidimensional Fatigue Inventory before and 6 months after surgery. Thirty-five patients were included in the analysis. Compared to baseline, GFAP showed a maximal increase at day 1 after surgery (p = 0.0005), tau peaked postoperatively on the day of surgery (p = 0.019), and NFL reached its maximum at day 5 after surgery (p < 0.0001). The increase in GFAP correlated with preoperative chiasmal compression (p = 0.020). The increase in tau was correlated with preoperative chiasmal (p = 0.011) and hypothalamus compression (p = 0.016), and fatigue score 6 months after surgery (p = 0.016). In conclusion, the concentrations of brain injury biomarkers in blood increased after ETSS for pituitary tumors. The results indicate that postoperative plasma GFAP and tau might reflect astroglial and neuronal damage after ETSS.

Postoperative diabetes insipidus: how to define and grade this complication?

PURPOSE

Although transient diabetes insipidus (DI) is the most common complication of pituitary surgery, there is no consensus on its definition. Polyuria is the most overt symptoms of DI, but can also reflect several physiological adaptive mechanisms in the postoperative phase. These may be difficult to distinguish from and might coincide with DI. The difficulty to distinguish DI from other causes of postoperative polyuria might explain the high variation in incidence rates. This limits interpretation of outcomes, in particular complication rates between centers, and may lead to unnecessary treatment. Aim of this review is to determine a pathophysiologically sound and practical definition of DI for uniform outcome evaluations and treatment recommendations.

METHODS

This study incorporates actual data and the experience of our center and combines this with a review of literature on pathophysiological mechanisms and definitions used in clinical studies reporting of postoperative DI.

RESULTS

The occurrence of excessive thirst and/or hyperosmolality or hypernatremia are the best indicators to discriminate between pathophysiological symptoms and signs of DI and other causes. Urine osmolality distinguishes DI from osmotic diuresis.

CONCLUSIONS

To improve reliability and comparability we propose the following definition for postoperative DI: polyuria (urine production > 300 ml/hour for 3 h) accompanied by a urine specific gravity (USG) < 1.005, and at least one of the following symptoms: excessive thirst, serum osmolality > 300 mosmol/kg, or serum sodium > 145 mmol/L. To prevent unnecessary treatment with desmopressin, we present an algorithm for the diagnosis and treatment of postoperative DI.

Nomogram predictive model of post-operative recurrence in non-functioning pituitary adenoma

Background

To analyze and predict the possibility of post-operative recurrence in non-functioning pituitary adenoma (NFPA) patients, we investigated the clinical factors leading to tumor recurrence and built a nomogram predictive model based on these risk factors.

Methods

A single-center retrospective study was performed. A total of 145 NFPA patients who underwent surgical treatment at Shenzhen People's Hospital from September 2013 to January 2019 were selected. Among them, 52 patients were diagnosed with recurrence of NFPA according to follow-up investigations. Binary logistic regression analysis was used to determine the significant risk factors. A nomogram model was then built to predict recurrence using these factors.

Results

The univariate analysis and the binary logistic regression analysis showed that age, tumor size, cavernous invasion, sphenoid sinus invasion, and surgical extension were significant factors affecting tumor recurrence. We then built a nomogram model to predict post-operative recurrence in NFPA patients using these factors. The correlation analysis indicated that sphenoid sinus invasion [hazard ratio (HR) =13.14, 95% confidence interval (CI): 7.03-24.58, P<0.0001], cavernous sinus invasion (HR =7.53, 95% CI: 4.27-13.28, P<0.0001), and tumor size (HR =11.06, 95% CI: 6.11-20.03, P<0.0001) could promote the recurrence of NFPA. In contrast, advanced age (HR =0.50, 95% CI: 0.28-0.86, P<0.0001) and gross total resection (HR =0.12, 95% CI: 0.07-0.22, P<0.0001) could effectively inhibit recurrence.

Conclusions

In this study, we developed a nomogram predictive model based on the significant recurrence-associated factors for NFPA. This nomogram may aid neurosurgeons in the post-operative prediction of recurrence, and may facilitate tailored counseling of individual patients.

Mass spectrometry-based proteomics analyses of post-translational modifications and proteoforms in human pituitary adenomas

Pituitary adenoma (PA) is a common intracranial neoplasm, which affects the hypothalamus-pituitary-target organ axis systems, and is hazardous to human health. Post-translational modifications (PTMs), including phosphorylation, ubiquitination, nitration, and sumoylation, are vitally important in the PA pathogenesis. The large-scale analysis of PTMs could provide a global view of molecular mechanisms for PA. Proteoforms, which are used to define various protein structural and functional forms originated from the same gene, are the future direction of proteomics research. The global studies of different proteoforms and PTMs of hypophyseal hormones such as growth hormone (GH) and prolactin (PRL) and the proportion change of different GH proteoforms or PRL proteoforms in human pituitary tissue could provide new insights into the clinical value of pituitary hormones in PAs. Multiple quantitative proteomics methods, including mass spectrometry (MS)-based label-free and stable isotope-labeled strategies in combination with different PTM-peptide enrichment methods such as TiO₂ enrichment of tryptic phosphopeptides and antibody enrichment of other PTM-peptides increase the feasibility for researchers to study PA proteomes. This article reviews the research status of PTMs and proteoforms in PAs, including the enrichment method, technical limitation, quantitative proteomics strategies, and the future perspectives, to achieve the goals of in-depth understanding its molecular pathogenesis, and discovering effective biomarkers and clinical therapeutic targets for predictive, preventive, and personalized treatment of PA patients.

Collagen Matrix With Mucoperiosteum Graft as an Effective Fatless Flapless Reconstruction After Endoscopic Pituitary Adenoma Resection

BACKGROUND

Proper skull base reconstruction after endoscopic endonasal pituitary surgery is of great importance to decrease the rate of complications.

OBJECTIVE

To assess the safety and efficacy of reconstruction with materials other than fat graft and naso-septal flaps (NSF) to avoid their associated morbidities.

METHODS

The authors' institutional database for patients who underwent endoscopic endonasal approach for pituitary adenoma was reviewed. Exclusion criteria included recurrence, postradiation therapy, and reconstruction by fat graft or NSF. They were divided into group A, where collagen matrix (CM) (DuraGen® Plus Matrix, Integra LifeSciences Corporation, Plainsboro, New Jersey) alone was used; group B, where CM and simple mucoperiosteum graft were used and group C, which included cases without CM utilization.

RESULTS

The study included 252 patients. No age, gender, or body mass index statistically significant difference between groups. Group B included the largest tumor size (23.0 mm) in comparison to groups A (18.0 mm) and C (13.0 mm). Suprasellar extension was more frequently present (49.4%) in comparison to groups A (29.8%, P = .001) and C (21.2%, P < .001). Postoperative cerebrospinal fluid (CSF) leak rate was 0%, 2.9%, and 6% in groups A, B, and C, respectively. In group B, the CSF leak rate decreased from 45.9% intraoperatively to 2.9% postoperatively (P < .001). In group A, the CSF leak reduction rate was almost statistically significant (P = .06).

CONCLUSION

Utilization of CM and simple mucosperiosteal graft in skull base reconstruction following pituitary adenoma surgery is an effective method to avoid the morbidities associated with NSF or fat graft.

Transcriptome and methylome analysis reveals three cellular origins of pituitary tumors

Pituitary adenomas (PA) are the second most common intracranial tumors. These neoplasms are classified according to the hormone they produce. The majority of PA occur sporadically, and their molecular pathogenesis is incompletely understood. The present transcriptomic and methylomic analysis of PA revealed that they segregate into three molecular clusters according to the transcription factor driving their terminal differentiation. First cluster, driven by NR5A1, consists of clinically non-functioning PA (CNFPA), comprising gonadotrophinomas and null cell; the second cluster consists of clinically evident ACTH adenomas and silent corticotroph adenomas, driven by TBX19; and the third, POU1F1-driven TSH-, PRL- and GH-adenomas, segregated together. Genes such as CACNA2D4, EPHA4 and SLIT1, were upregulated in each of these three clusters, respectively. Pathway enrichment analysis revealed specific alterations of these clusters: calcium signaling pathway in CNFPA; renin-angiotensin system for ACTH-adenomas and fatty acid metabolism for the TSH-, PRL-, GH-cluster. Non-tumoral pituitary scRNAseq data confirmed that this clustering also occurs in normal cytodifferentiation. Deconvolution analysis identify potential mononuclear cell infiltrate in PA consists of dendritic, NK and mast cells. Our results are consistent with a divergent origin of PA, which segregate into three clusters that depend on the specific transcription factors driving late pituitary cytodifferentiation.

Quantitative Analysis of Somatostatin and Dopamine Receptors Gene Expression Levels in Non-functioning Pituitary Tumors and Association with Clinical and Molecular Aggressiveness Features

The primary treatment for non-functioning pituitary tumors (NFPTs) is surgery, but it is often unsuccessful. Previous studies have reported that NFPTs express receptors for somatostatin (SST_1-5) and dopamine (DRDs) providing a rationale for the use of dopamine agonists and somatostatin analogues. Here, we systematically assessed SST_1-5 and DRDs expression by real-time quantitative PCR (RT-qPCR) in a large group of patients with NFPTs (n = 113) and analyzed their potential association with clinical and molecular aggressiveness features. SST_1-5 expression was also evaluated by immunohistochemistry. SST₃ was the predominant SST subtype detected, followed by SST₂, SST₅, and SST₁. DRD2 was the dominant DRD subtype, followed by DRD4, DRD5, and DRD1. A substantial proportion of NFPTs displayed marked expression of SST₂ and SST₅. No major association between SST_s and DRDs expression and clinical and molecular aggressiveness features was observed in NFPTs.

Size Matters: Rethinking of the Sizing Classification of Pituitary Adenomas Based on the Rates of Surgery: A Multi-institutional Retrospective Study of 29,651 Patients

Objective Pituitary adenomas are historically classified into microadenoma or macroadenomas based on size less than or greater than/equal to 1c m. “Giant” adenomas describe tumors ≥4 cm. The aim of this study is to present an evidence-based approach to size classification based on national trends.

Design The design involved is multi-institutional retrospective study.

Participants A total of 29,651 patients were studied from National Cancer Institute's SEER program from 2004 to 2016 across the United States.

Main Outcome Measures The main outcome measures include demographics, treatment characteristics, and overall survival in the population.

Results At the 20-mm threshold, the likelihood of operation exceeds the likelihood of nonoperative management. Patients with adenoma size 1 to 19 mm had significantly longer overall survival compared with 20 to 50 mm (Log rank: p < 0.0001). No survival difference was found between size 20 to 29 mm and larger. There was no significant difference in the rate of surgery between 30 to 39 mm and 40 to 50 mm tumors(p = 0.5035). Surgery group had a higher overall survival compared with nonsurgically managed patients (Log rank: p < 0.0001).

Conclusion Microadenoma has classically been used to describe pituitary tumors less than 1 cm, though no clinical significance of this threshold has been demonstrated. The current study suggests a size cut-off of 20 or 30 mm as more clinically relevant. Still, future studies are warranted to examine the significance of this classification by specific tumor type, and subclassified as appropriate. There is no difference in the rate of surgery or survival for adenomas between 30 and 50 mm, challenging the 4-mm cutoff threshold for “giant” adenoma.

Contemporary Management of Clinically Non-functioning Pituitary Adenomas: A Clinical Review

Non-functioning pituitary adenomas (NFPAs) are benign pituitary tumours that constitute about one-third of all pituitary adenomas. They typically present with symptoms of mass effects resulting in hypopituitarism, visual symptoms, or headache. Most NFPAs are macroadenomas (>1 cm in diameter) at diagnosis that can occasionally grow quite large and invade the cavernous sinus causing acute nerve compression and some patients may develop acute haemorrhage due to pituitary apoplexy. The progression from benign to malignant pituitary tumours is not fully understood; however, genetic and epigenetic abnormalities may be involved. Non-functioning pituitary carcinoma is extremely rare accounting for only 0.1% to 0.5 % of all pituitary tumours and presents with cerebrospinal, meningeal, or distant metastasis along with the absence of features of hormonal hypersecretion. Pituitary surgery through trans-sphenoidal approach has been the treatment of choice for symptomatic NFPAs; however, total resection of large macroadenomas is not always possible. Recurrence of tumours is frequent and occurs in 51.5% during 10 years of follow-up and negatively affects the overall prognosis. Adjuvant radiotherapy can decrease and prevent tumour growth but at the cost of significant side effects. The presence of somatostatin receptor types 2 and 3 (SSTR3 and SSTR2) and D2-specific dopaminergic receptors (D2R) within NFPAs has opened a new perspective of medical treatment for such tumours. The effect of dopamine agonist from pooled results on patients with NFPAs has emerged as a very promising treatment modality as it has resulted in reduction of tumour size in 30% of patients and stabilization of the disease in about 58%. Despite the lack of long-term studies on the mortality, the available limited evidence indicates that patients with NFPA have higher standardized mortality ratios (SMR) than the general population, with women particularly having higher SMR than men. Older age at diagnosis and higher doses of glucocorticoid replacement therapy are the only known predictors for increased mortality.

Pituitary tumors: epidemiology and clinical presentation spectrum

Pituitary tumors (PTs) are a heterogeneous group of lesions of the central nervous system that are usually benign. Most of them occur sporadically, but 5% can do so within family syndromes, usually at a young age. There are differences by sex, age, race, and genetic factors in the prevalence of different tumor cell types and clinical presentation. Functioning-PTs (FPTs) are usually diagnosed earlier than non-functioning PTs (NFPTs). However, this depends on the PT type. Headaches and visual disturbances are the most frequent mass-effect symptoms, but seizures or hydrocephalus may also occur. Pituitary apoplexy is another possible mode of presentation, and it requires special attention because of its potential severity. PTs in pregnancy, childhood, and old age present a series of clinical peculiarities that must be taken into account when evaluating these patients. Ectopic PTs (EPTs) are uncommon and share the same clinical-epidemiological data as eutopic PTs, but, depending on their location, other types of clinical manifestations may appear. Silent PTs are often detected as an incidentaloma or due to neurologic symptoms related to mass-effect. Aggressive PTs and pituitary carcinomas (PCs), which are very rare, are characterized by multiple local recurrences and metastases, respectively. This review addresses the epidemiology and clinical presentation of PTs, from the classical hormonal and mass-effect symptoms to the different rare presentations, such as pituitary apoplexy, hydrocephalus, or diabetes insipidus. Moreover, special situations of the presentation of PTs are discussed, namely, PTs in pregnancy, childhood, and the elderly, EPTs, silent and aggressive PTs, and PCs.

Application of the Three Points and Three Lines Method to Accurately Open the Sellar Floor in Microscopic Transsphenoidal Surgery of Pituitary Adenomas

OBJECTIVE

In this study, the sellar floor morphology of patients with pituitary adenoma is analyzed and a simple yet reliable method is identified to determine the location of bone window opening.

METHODS

Clinical information of 144 consecutively admitted patients was retrospectively analyzed. Enhanced magnetic resonance imaging of the midsagittal plane was selected as the reference for classifying the sellar floor. Intraoperative tumor location, extent of tumor resection, and follow-up results were analyzed for different types of sellar floor. The tuberculum sellae, lowest point of the sphenoid sinus, and the lowest point of the sellar floor and 3 lines related to them were used to classify the sellar floor. This is referred to as the "three points and three lines" method.

RESULTS

Based on its location in the sphenoid sinus, the sellar floor can be classified into 4 types: 12 patients (8.3%) with high sellar, 70 (48.6%) with medium sellar, 30 (20.8%) with low sellar, and 32 (22.8%) with steep sellar. The maximum tumor diameter, maximum sellar floor diameter, and the intercarotid distance were all significantly different among patients with different types of sellar floor (P < 0.001). For all patients, quick intraoperative location of the sellar floor opening was achieved. A total of 104 patients (72.2%) had total tumor resection, 28 (19.40%) had subtotal tumor resection, and 4 (2.8%) had partial tumor resection. Twenty patients (13.9%) experienced cerebrospinal fluid leak, and there was no significant difference in cerebrospinal fluid leak rate among groups.

CONCLUSIONS

Presurgical classification and location of the sellar floor are critical for understanding and assessing the transsphenoidal approach. Different types of sellar floor appeared in the surgery with different morphologic features. The three points and three lines method helps the surgeon to predetermine the location of the sellar floor opening and to shorten surgical time.

Cyclooxygenase enzyme and PGE2 expression in patients with functional and non-functional pituitary adenomas

BACKGROUND

Pituitary adenomas as multifactorial intracranial neoplasms impose a massive burden of morbidity on patients and characterizing the molecular mechanism underlying their pathogenesis has received considerable attention. Despite the appealing role of cyclooxygenase enzymes and their bioactive lipid products in cancer pathogenesis, their relevance to pituitary adenoma pathogenesis is debated and yet to be determined. Thus, the current study perused this relevance.

METHODS

The expression level of the isoforms of cyclooxygenase (COX-1 and COX-2) was evaluated in hormone-secreting and in-active pituitary adenoma tumors and normal pituitary tissues through Real-Time PCR. The level of PGE2, as the main product of enzymes, was assessed using enzyme immunoassay kits in patients and healthy subjects.

RESULTS

The results of the current study demonstrated that COX-1 and COX-2 expression levels were increased in pituitary tumors including non-functional pituitary adenoma (NFPA), acromegaly, Cushing's disease and prolactinoma compared with normal pituitary tissues. A significant expression level of COX-2 was observed in NFPA compared with the other pituitary tumors. Furthermore, the COX-2 expression level was significantly increased in macroadenoma and invasive tumors. The level of PGE2 was consistent with COX enzymes enhanced in pituitary adenoma tumors compared with healthy pituitary tissue. A significant elevation in the PGE2 level was detected in NFPA compared with hormone-secreting pituitary tumors. Additionally, the PGE2 level was increased in macroadenoma compared with microadenoma and in invasive compared with non-invasive pituitary tumors. The diagnostic values of cyclooxygenase isoforms and PGE2 were considerable between patients and healthy groups; however, COX-2 revealed more value in distinguishing endocrinologically active and non-active pituitary tumors.

CONCLUSIONS

Data from the current study provides expression patterns of COX-1, COX-2 and PGE2 in prevalent pituitary tumors and their association with patients' clinical features which may open up new molecular targets for early diagnosis/follow up of pituitary tumor growth.

Endoscopic versus nonendoscopic surgery for resection of pituitary adenomas: a national database study

OBJECTIVE

For symptomatic nonsecreting pituitary adenomas (PAs), resection remains a critical option for treatment. In this study, the authors used a large-population national database to compare endoscopic surgery (ES) to nonendoscopic surgery (NES) for the surgical management of PA.

METHODS

The National Cancer Database was queried for all patients diagnosed with histologically confirmed PA who underwent resection between 2010 and 2016 in which the surgical approach was specified. Due to database limitations, microsurgery and craniotomy were both categorized as NES.

RESULTS

Of 30,488 identified patients, 16,373 (53.7%) underwent ES and 14,115 (46.3%) underwent NES. There was a significant increase in the use of ES over time (OR 1.16, p < 0.01). Furthermore, there was a significant temporal increase in ES approach for tumors ≥ 2 cm (OR 1.17, p < 0.01). Compared to NES, patients who underwent ES were younger (p = 0.01), were treated at academic centers (p < 0.01), lived a greater distance from their treatment site (p < 0.01), had smaller tumors (p < 0.01), had greater medical comorbidity burden (p = 0.04), had private insurance (p < 0.01), and had a higher household income (p < 0.01). After propensity score matching to control for age, tumor size, Charlson/Deyo score, and type of treatment center, patients who underwent ES had a shorter length of hospital stay (LOS) (3.9 ± 4.9 days vs 4.3 ± 5.4 days, p < 0.01), although rates of gross-total resection (GTR; p = 0.34), adjuvant radiotherapy (p = 0.41), and 90-day mortality (p = 0.45) were similar. On multivariate logistic regression, African American race (OR 0.85, p < 0.01) and tumor size ≥ 2 cm (OR 0.89, p = 0.01) were negative predictors of receiving ES, whereas diagnosis in more recent years (OR 1.16, p < 0.01), greater Charlson/Deyo score (OR 1.10, p = 0.01), receiving treatment at an academic institution (OR 1.67, p < 0.01) or at a treatment site ≥ 20 miles away (OR 1.17, p < 0.01), having private insurance (OR 1.09, p = 0.01), and having a higher household income (OR 1.11, p = 0.01) were predictive of receiving ES. Compared to the ES cohort, patients who started with ES and converted to NES (n = 293) had a higher ratio of nonwhite race (p < 0.01), uninsured insurance status (p < 0.01), longer LOS (p < 0.01), and higher rates of GTR (p = 0.04).

CONCLUSIONS

There is an increasing trend toward ES for PA resection including its use for larger tumors. Although ES may result in shorter LOS compared to NES, rates of GTR, need for adjuvant therapy, and short-term mortality may be similar. Factors such as tumor size, insurance status, facility type, income, race, and existing comorbidities may predict receiving ES.

Molecular alterations in non-functioning pituitary adenomas

BACKGROUND

Clinically non-functioning Pituitary Adenomas (NFPA) are among the most common neoplasms of the sellar region. They usually present with compressive symptoms such as headache and visual field defects and not infrequently, are found incidentally. NFPA are classified as gonadotropinomas, null cell adenomas, according to their immunohistochemical phenotype. The molecular alterations responsible for the development of these lesions are incompletely understood, and there is scarce information regarding the molecular alterations and markers.

OBJECTIVE

We carried out an in-silico analysis aimed at identifying the molecular alterations in NFPA and to discover new molecular markers.

METHODS

Twenty-three microarray libraries were analyzed. Fourteen correspond to NFPA and 9 to control tissue gland. They were analyzed using Partek Genomic Suite to identify differentially expressed genes and WebGestalt and Metascape to understand the meaning behind the gene lists.

RESULTS

Pituitary adenomas showed a markedly different transcriptome compared to the non-tumoral gland, regardless of their putative immunophenotype. Genes related to calcium metabolism such as CACNA2D4, immune-related CXCR4, and stem cell-related KLF8 and PITX2 were altered.

CONCLUSIONS

Differentially expressed calcium metabolism and immune-related genes in NFPA represent attractive molecular markers and potential therapeutic targets.

Endoscopic endonasal resection of nonfunctioning pituitary adenoma with radiological calcification

OBJECTIVE

Radiological calcification in nonfunctioning pituitary adenoma is scarcely rare, which appears in various formations and raises special diagnostic and therapeutic challenges. Here we present our experience about the clinical aspects and treatment of calcified nonfunctioning pituitary adenoma.

METHODS

A total of 145 patients who underwent surgical resection of nonfunctioning pituitary adenomas via endoscopic endonasal approach from February 2008 to December 2018 were reviewed. Among these patients, cases with radiological calcifications on preoperative imaging were included in this study. We analyzed these patients' records, radiological neuroimaging, endocrine evaluation, operative notes as well as intraoperative videos.

RESULTS

Calcification on preoperative neuroimaging was observed in only 7 patients with nonfunctioning pituitary adenomas. The study population consisted of these seven patients with intra-tumor calcification (n = 2), thin and egg shelf-like capsular calcification (n = 3), hard and armor-like capsular calcification (n = 2). In 85.7% of cases (n = 6), nonfunctioning pituitary adenomas with calcification were characterized by soft tumor texture. Evidences demonstrated apoplexy occurred in 71.4% of cases with calcified pituitary adenomas (n = 5). Patients with intra-tumor calcification as well as with thin and egg shelf-like capsular calcification underwent resection of both tumor and calcification through extra-pseduocapusual dissection via endoscopic endonasal approach. Besides, in the remaining 2 cases (28.6%), hard and armor-like capsular calcification was found surrounding a soft tumor component; however, it did not interfere with adequate removal of the soft part via endoscopic endonasal approach with the hard calcification untouched. Postoperative course of all patients was uneventful. Long term follow-up (median interval of 49 months, range 8-70 months) showed that no recurrence occurred.

CONCLUSIONS

Although relatively rare, calcified nonfunctioning pituitary adenoma should be kept in mind to avoid making a wrong preoperative diagnosis. Given various calcification types, multiple surgical tactics is required accordingly. Extra-pseudocapusual resection via endoscopic endonasal approach is helpful for the resection of both adenoma and calcification.

Prolactinomas and nonfunctioning adenomas: preoperative diagnosis of tumor type using serum prolactin and tumor size

OBJECTIVE

Prolactinoma and nonfunctioning adenoma (NFA) are the most common sellar pathologies, and both can present with hyperprolactinemia. There are no definitive studies analyzing the relationship between the sizes of prolactinomas and NFAs and the serum prolactin level. Current guidelines for serum prolactin level cutoffs to distinguish between pathologies are suboptimal because they fail to consider the adenoma volume. In this study, the authors attempted to describe the relationship between serum prolactin level and prolactinoma volume. They also examined the predictive value that can be gained by considering tumor volume in differentiating prolactinoma from NFA and provide cutoff values based on a large sample of patients.

METHODS

A retrospective analysis of consecutive patients with prolactinomas (n = 76) and NFAs (n = 217) was performed. Patients were divided into groups based on adenoma volume, and the two pathologies were compared.

RESULTS

A strong correlation was found between prolactinoma volume and serum prolactin level (r = 0.831, p < 0.001). However, there was no significant correlation between NFA volume and serum prolactin level (r = -0.020, p = 0.773). Receiver operating characteristic curve analysis of three different adenoma volume groups was performed and resulted in different serum prolactin level cutoffs for each group. For group 1 (≤ 0.5 cm3), the most accurate cutoff was 43.65 μg/L (area under the curve [AUC] = 0.951); for group 2 (> 0.5 to 4 cm3), 60.05 μg/L (AUC = 0.949); and for group 3 (> 4 cm3), 248.15 μg/L (AUC = 1.0).

CONCLUSIONS

Prolactinoma volume has a significant impact on serum prolactin level, whereas NFA volume does not. This finding indicates that the amount of prolactin-producing tissue is a more important factor regarding serum prolactin level than absolute adenoma volume. Hence, volume should be a determining factor to distinguish between prolactinoma and NFA prior to surgery. Current serum prolactin threshold level guidelines are suboptimal and cannot be generalized across all adenoma volumes.

Quantitative Analysis of Ubiquitinated Proteins in Human Pituitary and Pituitary Adenoma Tissues

Protein ubiquitination is an important post-translational modification that is associated with multiple diseases, including pituitary adenomas (PAs). Protein ubiquitination profiling in human pituitary and PAs remains unknown. Here, we performed the first ubiquitination analysis with an anti-ubiquitin antibody (specific to K-ε-GG)-based label-free quantitative proteomics method and bioinformatics to investigate protein ubiquitination profiling between PA and control tissues. A total of 158 ubiquitinated sites and 142 ubiquitinated peptides in 108 proteins were identified, and five ubiquitination motifs were found. KEGG pathway network analysis of 108 ubiquitinated proteins identified four statistically significant signaling pathways, including PI3K-AKT signaling pathway, hippo signaling pathway, ribosome, and nucleotide excision repair. R software Gene Ontology (GO) analysis of 108 ubiquitinated proteins revealed that protein ubiquitination was involved in multiple biological processes, cellular components, and molecule functions. The randomly selected ubiquitinated 14-3-3 zeta/delta protein was further analyzed with Western blot, and it was found that upregulated 14-3-3 zeta/delta protein in nonfunctional PAs might be derived from the significantly decreased level of its ubiquitination compared to control pituitaries, which indicated a contribution of 14-3-3 zeta/delta protein to pituitary tumorigenesis. These findings provided the first ubiquitinated proteomic profiling and ubiquitination-involved signaling pathway networks in human PAs. This study offers new scientific evidence and basic data to elucidate the biological functions of ubiquitination in PAs, insights into its novel molecular mechanisms of pituitary tumorigenesis, and discovery of novel biomarkers and therapeutic targets for effective treatment of PAs.