Patterns of extrasellar extension in growth hormone–secreting and nonfunctional pituitary macroadenomas

Clinical Significance of T2-Weighted Sequence Intensity on Magnetic Resonance Imaging in Clinically Non-Functioning Pituitary Adenomas

BACKGROUND

Little is known about the relationship between signal intensity patterns on T2-weighted magnetic resonance imaging (MRI) in non-functioning pituitary adenomas (NFPAs).

OBJECTIVE

In this study, the clinical, hormonal, histological features, and therapeutic responses were evaluated according to the T2 signal intensity in NFPAs.

METHODS

This retrospective and multicenter study included a group of 166 NFPA patients (93 men, 56%, mean age 58.5 ±14.8 yr).

RESULTS

Approximately half of the tumors (n=84, 50.6%) were hyperintense, while 34.3% (n=57) and 15.1% (n=25) were iso- and hypointense, respectively. The median maximum tumor diameter of the isointense group [16 (13-25) mm] was significantly lower than that of the hyperintense [23 (16.6-29.7) mm] group (p=0.003). Similarly, the tumor volume of the isointense group [1,523 (618-5,226) mm3] was significantly lower than that of the hyperintense [4,012 (2,506-8,320) mm3] group (p=0.002). Chiasmatic compression occurred less frequently in tumors with isointense signal characteristics (38.6%) compared to tumors with hypointense (68%) and hyperintense (65.5%) signal characteristics (p=0.003). Invasive adenomas (p=0.001) and the degree of cavernous sinus invasion (p<0.001) were more frequent in the hyperintense adenoma group compared to the remaining groups. Plurihormonal tumors and silent lactotroph adenomas were more frequent in the isointense tumor group.

CONCLUSION

In conclusion, hyperintensity on T2-weighted MRI in NFPAs is associated with larger and more invasive tumors compared to isointense NFPAs.

Predictive value of suprasellar extension for intracranial infection after endoscopic transsphenoidal pituitary adenoma resection

OBJECTIVE

To investigate the relationship between suprasellar extension (SSE) and intracranial infection after endoscopic endonasal transsphenoidal approach (EETA) for pituitary adenoma resection.

METHODS

We retrospectively analyzed 94 patients with suprasellar extended pituitary adenoma admitted to the Department of Neurosurgery of the Affiliated Hospital of Guilin Medical College from January 2018 to December 2021. We measured the preoperative magnetic resonance sagittal SSE and collected clinical data and divided the patients into groups according to the presence of postoperative intracranial infection. The critical value for the SSE was calculated by using a working characteristic curve for the subjects. The risk factors for intracranial infection after EETA resection of pituitary adenomas were analyzed by multivariate regression analysis.

RESULTS

Among the 94 patients, 12 cases (12.8%) were placed in the infection group and 82 cases (87.2%) in the non-infection group. The cut-off value for the SSE in the sagittal position was 15.6 mm, the sensitivity was 75%, the specificity was 87.8%, and the area under the curve (AUC) was 0.801. The coronary cut-off value for the SSE was 15.8 mm, the sensitivity was 66.7%, the specificity was 79.3%, and the AUC was 0.787. The SSE values in the sagittal and coronal positions were correlated with postoperative intracranial infection (P < 0.05). After univariate analysis, those with significant differences were included in the multivariate regression analysis. It was concluded that the extension distance of the tumor above the sella in the sagittal position was ≥ 15.6 mm, the tumor texture was hard, and the postoperative cerebrospinal fluid leakage were the independent risk factors for intracranial infection after EETA resection of suprasellar extended pituitary tumors (P < 0.05).

CONCLUSIONS

The value of SSE on sagittal MRI can predict intracranial infection in patients with suprasellar extended pituitary adenoma after endoscopic endonasal transsphenoidal resection. This finding recommends neurosurgeons pay more attention to the imaging characteristics of pituitary adenomas and select appropriate treatment plans in combination with the intraoperative conditions to reduce the incidence of intracranial infection.

Anatomical variations of the cavernous Internal Carotid Artery: Validation of an MRI-based classification

OBJECTIVE

Variations of the cavernous Internal Carotid Artery (ICA) angulation (C4-bend) have been classified into 4 anatomical subtypes with particular surgical relevance, as a very angulated ICA comes in closest contact with the pituitary gland leading to higher risk of iatrogenic vascular injury. This study aimed to validate this classification using current routine imaging techniques.

METHODS

The different cavernous ICA bending angles were measured on 109 MRI TOF sequences, within a retrospective database of patients with no sellar lesions. Each ICA was classified into one of 4 anatomical subtypes as already defined in a previous study [1]. Interrater agreement was assessed by a Kappa Correlation Coefficient.

RESULTS

Kappa Correlation Coefficient was of 0.90 [0.82-0.95], validating the strong level of agreement between all observers when using the present classification.

CONCLUSION

Classification of the cavernous ICA in 4 subtypes appears statistically valid on routinely used pre-operative MRI, providing an efficient tool to estimate the vascular iatrogenic risk prior to endoscopic endonasal transsphenoidal surgery.

Multidisciplinary management of difficult/aggressive growth-hormone pituitary neuro-endocrine tumors

Growth Hormone-secreting adenomas exhibits variable biological behavior and heterogeneous natural history, ranging from small adenomas and mild disease, to invasive and aggressive neoplasms with more severe clinical picture. Patients not cured or controlled after neurosurgical and first-generation somatostatin receptor ligands (SRL) therapy could require multiple surgical, medical and/or radiation treatments to achieve disease control. To date, no clinical, laboratory, histopathological, or neuroradiological markers are able to define the aggressiveness or predict the disease prognosis in patients with acromegaly. Therefore, the management of these patients requires careful evaluation of laboratory assessments, diagnostic criteria, neuroradiology examinations, and neurosurgical approaches to choose an effective and patient-tailored medical therapy. A multidisciplinary approach is particularly useful in difficult/aggressive acromegaly to schedule multimodal treatment, which includes radiation therapy, chemotherapy with temozolomide and other, recent emerging treatments. Herein, we describe the role of the different members of the multidisciplinary team according to our personal experience; a flow-chart for the therapeutic approach of difficult/aggressive acromegaly patients is proposed.

A current perspective of pituitary adenoma MRI characteristics: a review

INTRODUCTION

MR imaging is an essential and fundamental tool in the diagnosis, management, and follow-up of patients with pituitary adenomas (PAs). Recent advances have continued to enhance the usefulness of this imaging modality.

AREAS COVERED

This article focuses on signal intensity patterns of PAs and associated clinical characteristics, vertical extension patterns, and cavernous sinus invasion with a special focus on the clinical implications that arise. A search using Medline and Google Scholar was conducted using different combinations of relevant keywords, giving preference to recent publications.

EXPERT OPINION

A higher proportion of GH-secreting PAs are hypointense on T2 weighted images compared to other tumor subtypes. Hypointense tumors are generally smaller compared to hyperintense ones, and among the GH-secreting subgroup, a better response to somatostatin analogue treatment was noted together with an association for a densely granulated pattern. Nonfunctional PAs show a predilection to extend upwards while GH-secreting PAs and prolactinomas show a predominantly inferior extension growth pattern. Further studies to better understand the mechanisms responsible for this behavior are anticipated. Further development, refining and validation of predictive scoring systems for tumor behavior might be useful adjuncts in the management of patients with PAs.

Giant Non-Functioning Pituitary Adenomas: Treatment Considerations

Giant pituitary adenomas are a subgroup of pituitary adenomas defined by a diameter greater than 4 cm, and they account for 5–14% of adenomas in surgical series. Because of their growth patterns and locations, often involving critical neurovascular structures, they represent a true surgical challenge, and gross total resection is difficult to achieve. There is no consensus on the optimal surgical strategy for giant pituitary adenomas, and, often, integrated multi-staged treatment strategies have been considered. Transcranial or transsphenoidal approaches, alone or combined, according to tumor and patient features are the two main routes. Each of these strategies has pros and cons. The conventional transcranial approach has for a long time been considered the first choice for the removal of giant pituitary adenomas. Currently, with endoscopic techniques, it is also possible to remove lesions that involve the intradural compartment and the adjacent neurovascular structures with the use of extended approaches. Our policy for the management of these lesions is to adopt the endoscopic endonasal approach as the first choice unless the tumor presents significant intracranial extension that results in it being outside the visibility and maneuverability of the endoscopic endonasal route. In these latter cases, we agree that the transcranial approach is more appropriate. However, accurate preoperative evaluation and refined treatment plans for each patient are mandatory to define a proper strategy in order to achieve the most effective long-term result.

Dumbbell-shaped pituitary adenomas: prognostic factors for prediction of tumor nondescent of the supradiaphragmal component from a multicenter series

OBJECTIVE

Dumbbell-shaped pituitary adenomas (DSPAs) are a subgroup of macroadenomas with suprasellar extension that are characterized by a smaller diameter at the level of the diaphragma sellae opening compared with the supradiaphragmal tumor component (SDTC). Hence, DSPAs may be particularly prone to a nondescending suprasellar tumor component and risk for residual tumor or postoperative bleeding.

METHODS

A multicenter retrospective cohort analysis of 99 patients with DSPA operated on via direct endoscopic endonasal transsphenoidal approach between 2011 and 2020 was conducted. Patient recruitment was performed at two tertiary care centers (Medical University of Vienna and University of Southern California) with expertise in endoscopic skull base surgery. DSPA was defined as having a smaller diameter at the level of the diaphragma sellae compared with the SDTC.

RESULTS

On preoperative MRI, all DSPAs were macroadenomas (maximum diameter range 17-71 mm, volume range 2-88 cm3). Tumor descent was found in 73 (74%) of 99 patients (group A), and nondescent in 26 (26%) of 99 patients (group B) intraoperatively. DSPAs in group A had a significantly smaller diameter (30 vs 42 mm, p < 0.001) and significantly smaller volume (10 vs 22 cm3, p < 0.001) than those in group B. The ratio of the minimum area at the level of the diaphragmal opening in comparison with the maximum area of the suprasellar tumor component ("neck-to-dome area") was significantly lower in group A than in group B (1.7 vs 2.7, p < 0.001). Receiver operating characteristic curve analysis revealed an area under the curve of 0.75 (95% CI 0.63-0.87). At a cutoff ratio of 1.9, the sensitivity and specificity for a nondescending suprasellar tumor component were 77% and 34%, respectively.

CONCLUSIONS

In the present study, the neck-to-dome area ratio was of prognostic value for prediction of intraoperative tumor nondescent in DSPAs operated on via a direct endonasal endoscopic approach. Pituitary adenoma SDTC nondescent carried the inherent risk of hemorrhagic transformation in all cases.

The medial wall and medial compartment of the cavernous sinus: an anatomic study using plastinated histological sections

The medial wall of the cavernous sinus (CS) has a significant role in evaluation and treatment of pituitary adenomas. This study was conducted to clarify the fine architecture of the medial wall and medial compartment of the CS at both macro- and micro-levels in twenty-one human cadaveric heads by using the epoxy sheet plastination technique. The sellar part medial wall is an intact dural layer that separates the CS from the pituitary gland. This dural wall adhered to the diaphragma sellae and the periosteum of the sella turcica to form fibrous triangles. Eight micro-protrusions of the pituitary gland were found at both sides of that wall. The thickness of the sellar part medial wall at its central portion was significantly thinner than that at the other surrounding portions. From the superior view, tortuous intracavernous carotid arteries can be divided into outward bending type and inward bending type. The inward bending intracavernous carotid was apt to bent towards the central part of the sellar part medial wall, where there were usually wide and short fibrous bands with more densely stained connective tissues between them. The micro-protrusion of the pituitary gland in the medial wall of the CS could provide an anatomical basis for the occult tumor invasion and the recurrence of residual tumor. Different bending facing states of tortuous intracavernous carotid arteries in the lateral direction may be a factor of the determination of the direction of growth of pituitary tumors.

Prospective intraoperative and histologic evaluation of cavernous sinus medial wall invasion by pituitary adenomas and its implications for acromegaly remission outcomes

Recurrence and biochemical remission rates vary widely among different histological subtypes of pituitary adenoma. In this prospective study, we evaluated 107 consecutive primary pituitary adenomas operated on by a single neurosurgeon including 28 corticotroph, 27 gonadotroph, 24 somatotroph, 17 lactotroph, 5 null-cell and 6 plurihormonal. In each case, we performed direct endoscopic intraoperative inspection of the medial wall of the cavernous sinus, which was surgically removed when invasion was visualized. This was performed irrespective of tumor functional status. Medial wall resection was performed in 47% of pituitary adenomas, and 39/50 walls confirmed pathologic evidence of invasion, rendering a positive predictive value of intraoperative evaluation of medial wall invasion of 78%. We show for the first-time dramatic disparities in the frequency of medial wall invasion among pathological subtypes. Somatotroph tumors invaded the medial wall much more often than other adenoma subtypes, 81% intraoperatively and 69% histologically, followed by plurihormonal tumors (40%) and gonadotroph cell tumors (33%), both with intraoperative positive predictive value of 100%. The least likely to invade were corticotroph adenomas, at a rate of 32% intraoperatively and 21% histologically, and null-cell adenomas at 0%. Removal of the cavernous sinus medial wall was not associated with permanent cranial nerve morbidity nor carotid artery injury, although 4 patients (all Knosp 3-4) experienced transient diplopia. Medial wall resection in acromegaly resulted in the highest potential for biochemical remission ever reported, with an average postoperative day 1 GH levels of 0.96 ug/L and surgical remission rates of 92% based on normalization of IGF-1 levels after surgery (mean = 15.56 months; range 3-30 months). Our findings suggest that tumor invasion of the medial wall of the cavernous sinus may explain the relatively low biochemical remission rates currently seen for acromegaly and illustrate the relevance of advanced intradural surgical approaches for successful and durable outcomes in endonasal pituitary surgery for functional adenomas.

Growth hormone secreting pituitary adenomas show distinct extrasellar extension patterns compared to nonfunctional pituitary adenomas

PURPOSE

Patterns of extension of pituitary adenomas (PA) may vary according to PA subtype. Understanding extrasellar extension patterns in growth hormone PAs (GHPA) vis-a-vis nonfunctional PAs (NFPAs) may provide insights into the biology of GHPA and future treatment avenues.

METHODS

Preoperative MR imaging (MRI) in 179 consecutive patients treated surgically for NFPA (n = 139) and GHPA (n = 40) were analyzed to determine patterns of extrasellar growth. Extension was divided into two principal directions: cranio-caudal (measured by infrasellar/suprasellar extension), and lateral cavernous sinus invasion (CSI) determined by Knosp grading score of 3-4. Suprasellar extension was defined as tumor extension superior to the tuberculum sellae- dorsum sellae line, and inferior extension as invasion through the sellar floor into the sphenoid sinus or clivus. Categorical analysis was performed using Fisher's exact test.

RESULTS

GHPAs were overall more likely to remain purely intrasellar compared to NFPA (50% vs 26%, p < 0.001). GHPAs, however, were 7 times more likely to exhibit isolated infrasellar extension compared to NFPA (20% vs 2.8%, p = 0.001). Conversely, NFPAs were twice as likely to exhibit isolated suprasellar extension compared to GHPA (60% vs 28%, p < 0.001), as well as combined suprasellar/infrasellar extension (25% vs 3%, p = 0.011). There were no overall differences in CSI between the two subgroups.

DISCUSSION

GHPA and NFPA demonstrate distinct extrasellar extension patterns on MRI. GHPAs show proclivity for inferior extension with bony invasion, whereas NFPAs are more likely to exhibit suprasellar extension through the diaphragmatic aperture. These distinctions may have implications into the biology and future treatment of PAs.

Implications of Heterogeneity of Epithelial-Mesenchymal States in Acromegaly Therapeutic Pharmacologic Response

Acromegaly is caused by excess growth hormone (GH) produced by a pituitary tumor. First-generation somatostatin receptor ligands (SRLs) are the first-line treatment. Several studies have linked E-cadherin loss and epithelial-mesenchymal transition (EMT) with resistance to SRLs. Our aim was to study EMT and its relationship with SRLs resistance in GH-producing tumors. We analyzed the expression of EMT-related genes by RT-qPCR in 57 tumors. The postsurgical response to SRLs was categorized as complete response, partial response, or nonresponse if IGF-1 was normal, had decreased more than 30% without normalization, or neither of those, respectively. Most tumors showed a hybrid and variable EMT expression profile not specifically associated with SRL response instead of a defined epithelial or mesenchymal phenotype. However, high SNAI1 expression was related to invasive and SRL-nonresponsive tumors. RORC was overexpressed in tumors treated with SRLs before surgery, and this increased expression was more prominent in those cases that normalized postsurgical IGF-1 levels under SRL treatment. In conclusion, GH-producing tumors showed a heterogeneous expression pattern of EMT-related genes that would partly explain the heterogeneous response to SRLs. SNAI1 and RORC may be useful to predict response to SRLs and help medical treatment decision making.

Baseline MRI findings as predictors of hypopituitarism in patients with non-functioning pituitary adenomas

Hypopituitarism tends to occur in large pituitary adenomas. However, similar tumors could present with strikingly different hormonal deficiencies. In this study, we looked at MRI characteristics in non-functioning pituitary adenomas (NFPA), which could predict secondary adrenal insufficiency (SAI) and central hypothyroidism (CHT). We reviewed the files of patients with NFPA attending our clinic. Tumor size, invasiveness, MR-signal intensity, and gadolinium enhancement in preoperative MRI were recorded along with documented presurgical hypopituitarism profile. Logistic regression was used to predict SAI, CHT, or both (SAI/CHT) based on MRI and demographic parameters. Receiver operating characteristic curves were used to determine their diagnostic utility. One hundred twenty-one patients were included in the study. Older age (P = 0.021), male sex (P = 0.043), stalk deviation (P < 0.0001), contrast enhancement (P = 0.029), and optic chiasma compression (P = 0.012) were associated with SAI/CHT. Adenoma vertical height, largest diameter, and estimated volume were also strongly associated with SAI/CHT (P < 0.0001). These associations remained significant in a multivariate analysis. No tumor smaller than 12 mm in vertical height, 17 mm in largest diameter, or 0.9 cm3 in volume was associated with SAI/CHT. At cut-off ≥18 mm for vertical height, ≥23 mm for largest diameter, and ≥3.2 cm3 the sensitivity was around 90-92% for detecting SAI/CHT. Only vertical height was significantly associated with any one or more pituitary hormonal deficit (P = 0.001). In conclusion, adenoma size, independent of the measurement used, remains the best predictor of SAI/CHT in NFPA. Dynamic testing to rule out SAI is probably indicated in adenomas larger than 18 mm vertical height, 23 mm largest diameter and 3.2 cm3 adenoma volume.

Evaluation of the Gross Total Resection Rate of Suprasellar Pituitary Macroadenomas with and without the Removal of the Tuberculum Sellae Bone

OBJECTIVE

Improving the gross total resection (GTR) rate of suprasellar pituitary macroadenomas (SPMAs) using the pure endoscopic endonasal transsphenoidal approach (EETA) has been a long-standing focus of neurosurgeons. This study was aimed at evaluating the influences of the removal of the tuberculum sellae bone (TSB) without opening the dura of the tuberculum sellae on the GTR rate of SPMAs via the EETA.

METHODS

We retrospectively analyzed medical reports of patients with SPMAs who underwent EETA between February 2015 and November 2020. Data on clinical manifestations, endocrinologic types, imaging features (Hardy classification, morphology, and texture), clinical outcomes, and TSB removal status were collected. All patients were followed up for 6 months postoperatively.

RESULTS

Seventy-eight patients were enrolled in our study. The GTR rates of the TSB removal group (45/78, 57.7%) and nonremoval group (33/78, 42.3%) were 80.0% (36/45) and 57.6% (19/33), respectively. Univariate logistic regression analysis found that the removal of TSB, rounded morphology, and low Hardy classification were correlated with higher GTR rates. Multiple logistic regression analysis indicated that even after adjusting for tumor types and imaging features, the removal of TSB had an independent effect on the GTR rate (odds ratio, 7.6; 95% confidence interval, 1.8-31.6; P = 0.005). The incidence rates of postoperative cerebrospinal fluid leakage and diabetes insipidus were not significantly different between the TSB removal group and TSB nonremoval group.

CONCLUSIONS

TSB removal using EETA without opening the tuberculum sellae dura improves the GTR rate of SPMAs without increasing the incidence of postoperative complications.

Patterns of extrasellar invasive growth of pituitary adenomas with normal sellar cavity size

BACKGROUND

Pituitary adenomas (PAs) are among the most common brain tumors which characteristically become symptomatic due to the mass effect on surrounding structures and/or hormonal imbalances. This study describes 28 cases of PAs with an extrasellar invasive growth (EIG) at the early stage of tumor growth with normal sellar cavity size.

METHODS

1200 cases of PAs either treated medically or via Endoscopic transsphenoidal surgery were reviewed during a 10-year period. Pre-operative imaging was analyzed to evaluate the tumor expansion pattern, tumor invasion sites and other relevant tumor properties. A comprehensive preoperative endocrinological along with postoperative histopathological studies were conducted to evaluate the subjects' homeostasis and further identify the lesions characteristics.

RESULTS

Of the 28 patients, patients 19, 2, 1 and 6 had a growth hormone (GH)-secreting PA, an adrenocorticotropic hormone (ACTH)-secreting PA, a nonfunctional PA (NFPA) and a mix-hormones secreting PA, respectively. There was a statistically significant difference between patients with and without EIG regarding types of PAs (P = 0.000). Post-hoc tests demonstrated that GH-secreting PAs (P = 0.0003) and mix-hormones secreting PAs (P = 0.0000) are significantly more invasive, while NFPAs (P = 0.0000) are less invasive. There was not a statistically significant difference between the invasion sites and different types of PAs (P = 0.122).

CONCLUSION

Among different histological subtypes of PAs, GH-secreting PAs revealed a remarkable tendency for EIG with normal sellar cavity size. The extra-sellar tumor extension with a normal sella did not correlate with atypical histology. Considering EIG patterns, surgeons should be vigilant to investigate and follow the tumor spreading to its enclosing boundary during surgery, the clival part of sphenoid bone should be more exposed, and both inferomedial and lateral borders of the sphenoid sinus should be carefully explored in order to remove the tumor.

Association of an empty sella and grave´s disease in a patient with acromegaly: a case report

Acromegaly is, in most cases, caused by growth hormone secreting pituitary adenomas. Those patients often develop different pathologies of the thyroid gland, however, the occurrence of Grave´s disease is quite a rare situation. We report a case of a 64-year-old female patient who presented with signs of hyperthyroidism and imbalance of her diabetes mellitus. On physical examination, she had facial features of acromegaly. Biochemical testing confirmed the suspicion of acromegaly and Grave´s disease, with an elevated insulin-like growth factor-1 and a suppressed thyroid stimulation hormone (TSH) with positive TSH-receptor antibodies. A pituitary Magnetic Resonance Imaging (MRI) was performed, revealing a macro-adenoma and an empty sella. The patient successfully underwent a transsphenoidal surgery and obtained a remission of her hyperthyroidism under anti-thyroid drugs.

Safety and Effectiveness of the Direct Endoscopic Endonasal Approach for Primary Sellar Pathology: A Contemporary Case Series of More Than 400 Patients

BACKGROUND

The direct endoscopic endonasal approach (EEA) has become the primary technique used for resection of sellar pathology, meriting investigation into the risk factors for complications and predictors of postoperative outcomes after direct EEA.

METHODS

We retrospectively analyzed the patient and tumor characteristics from 404 patients who had undergone direct EEA for sellar pathology at the USC Pituitary Center from September 2011 to December 2019.

RESULTS

Of the 404 pathologic entities included, 349 (86%) were pituitary adenomas (PAs), 29 (7%) were Rathke cleft cysts, and 26 (6%) were other sellar lesions. The mean lesion diameter was 2.3 cm, with 34 microadenomas (10%) and 315 macroadenomas (90%). Cavernous sinus invasion was present in 39% of the PAs. No patient died. The surgical complications included internal carotid artery injury without neurological sequelae (0.2%), vision loss (0.7%), meningitis (0.7%), cerebrospinal fluid leak (4%), epistaxis (4%), sinusitis (1%), transient cranial nerve paresis (0.5%), and postoperative abscess (0.25%). New hypopituitarism developed in 3%. Gross total resection was achieved in 208 PA cases (58%). Clinical improvement of headaches and visual deficits were reported for 67% and 76% of cases, respectively. Hormonal remission was achieved in 82% of patients with functional PAs. The median hospital stay was 2 days, with 34 patients (8%) readmitted within 30 days and 10 (3%) undergoing early reoperation. Disease recurrence or progression developed in 10% and was less likely in the case of gross total resection and apoplexy.

CONCLUSION

In the present, large, consecutive, mostly single-surgeon series, the patients experienced clinical improvement in most preoperative symptoms and had low rates of perioperative morbidity. We have demonstrated that direct EEA can be efficiently, safely, and successfully performed by a neurosurgical team.

Intraoperative lumbar drainage can prevent cerebrospinal fluid leakage during transsphenoidal surgery for pituitary adenomas: a systematic review and meta-analysis

Background

Perioperative cerebrospinal fluid (CSF) leakage is a major complication of pituitary adenomas transsphenoidal surgery. Lumbar drainage (LD) is a common method of treating CSF leakage. But whether intraoperative LD can prevent CSF leakage during the perioperative period of pituitary adenomas transsphenoidal surgery remains controversial. Clarity on the appropriate use of LD is needed.

Methods

A systematic literature review was conducted in the PubMed, EMBASE, and Web of science databases. Articles were included when they compared intraoperative LD with intraoperative no-LD CSF leakage rates during pituitary adenomas transsphenoidal surgery.

Results

Overall, 5 studies containing 678 cases met the inclusion criteria. When data were provided on intraoperative CSF leakage rates, the meta-analysis showed a significant difference in favor of intraoperative LD. When data were provided on postoperative CSF leakage rates, the meta-analysis also demonstrated a significant difference in favor of intraoperative LD.

Conclusions

Although the results of this meta-analysis suggest intraoperative LD can reduce the risk of CSF leakage during the perioperative period of pituitary adenomas transsphenoidal surgery, the available evidence is indefinite. To some extent the results suggest intraoperative LD’s potential positive role. Further studies that include well-designed prospective, randomized controlled clinical trials are necessary for further verification.

Development and clinical validation of a grading system for pituitary adenoma consistency

OBJECTIVE

Pituitary adenoma (PA) consistency, or texture, is an important intraoperative characteristic that may dictate operative dissection techniques and/or instruments used for tumor removal during endoscopic endonasal approaches (EEAs). The impact of PA consistency on surgical outcomes has yet to be elucidated.

METHODS

The authors developed an objective 5-point grading scale for PA consistency based on intraoperative characteristics, including ease of tumor debulking, manipulation, and instrument selection, ranging from cystic/hemorrhagic tumors (grade 1) to calcified tumors (grade 5). The proposed grading system was prospectively assessed in 306 consecutive patients who underwent an EEA for PAs, and who were subsequently analyzed for associations with surgical outcomes, including extent of resection (EOR) and complication profiles.

RESULTS

Institutional database review identified 306 patients who underwent intraoperative assessment of PA consistency, of which 96% were macroadenomas, 70% had suprasellar extension, and 44% had cavernous sinus invasion (CSI). There were 214 (69.9%) nonfunctional PAs and 92 functional PAs (31.1%). Distribution of scores included 15 grade 1 tumors (4.9%), 112 grade 2 tumors (36.6%), 125 grade 3 tumors (40.8%), 52 grade 4 tumors (17%), and 2 grade 5 tumors (0.7%). Compared to grade 1/2 and grade 3 PAs, grade 4/5 PAs were significantly larger (22.5 vs 26.6 vs 27.4 mm, p < 0.01), more likely to exhibit CSI (39% vs 42% vs 59%, p < 0.05), and trended toward nonfunctionality (67% vs 68% vs 82%, p = 0.086). Although there was no association between PA consistency and preoperative headaches or visual dysfunction, grade 4/5 PAs trended toward preoperative (p = 0.058) and postoperative panhypopituitarism (p = 0.066). Patients with preoperative visual dysfunction experienced greater improvement if they had a grade 1/2 PA (p < 0.05). Intraoperative CSF leaks were noted in 32% of cases and were more common with higher-consistency-grade tumors (p = 0.048), although this difference did not translate to postoperative CSF leaks. Gross-total resection (%) was more likely with lower PA consistency score as follows: grade 1/2 (60%), grade 3 (50%), grade 4/5 (44%; p = 0.045). Extracapsular techniques were almost exclusively performed in grade 4/5 PAs. Assignment of scores showed low variance and high reproducibility, with an intraclass correlation coefficient of 0.905 (95% CI 0.815-0.958), indicating excellent interrater reliability.

CONCLUSIONS

These findings demonstrate clinical validity of the proposed intraoperative grading scale with respect to PA subtype, neuroimaging features, EOR, and endocrine complications. Future studies will assess the relation of PA consistency to preoperative MRI findings to accurately predict consistency, thereby allowing the surgeon to tailor the exposure and prepare for varying resection strategies.

Anatomic and histologic features of diaphragma sellae that effects the suprasellar extension

This study aimed to determine the anatomical and histological features of diaphragma sellae that affect the suprasellar extension of intrasellar tumours. Twenty-four fresh adult cadavers were dissected for the study. Diaphragma sellae and pituitary capsules with sellar structures were resected. The diaphragma sellae was anatomically reviewed in detail. Immunohistochemical staining was performed for collagen types I, II, III, and IV. We examined the suprasellar growth of 13 sellar tumours extending superiorly through the diaphragma sellae by performing a series of 2704 endoscopic transnasal operations to analyse the anatomic and histologic results of the study. The diameter of the foramen of diaphragma sellae varied between specimens. Of 24 specimens, the diaphragma sellae in five (21%) had a tight-type foramen and those in 19 (79%) were more spacious. An increased expression of collagen types I and IV was observed in the pituitary capsule and the diaphragma sellae. In this clinical series, we observed that all types of sellar tumours could expand through the foramen. We observed radiologically and intraoperatively that the diaphragma sellae was displaced laterally and formed a dome in two cases with an adenoma extending to the suprasellar area. Two types of suprasellar extension through the diaphragma sellae are possible: 1) The collagen structure of diaphragma sellae can be destroyed by invasive tumours; 2) The morphology of the foramen of the diaphragma sellae facilitates suprasellar tumoural extension. All sellar tumours, including non-invasive cystic tumours, may invade the suprasellar area by expanding through the foramen of the diaphragma sellae.

Differential Clinical Presentation, Intraoperative Management Strategies, and Surgical Outcomes After Endoscopic Endonasal Treatment of Cystic Sellar Masses

BACKGROUND

Cystic sellar masses (CSMs) pose diagnostic and therapeutic challenges associated with subtotal cyst wall resection, cerebrospinal fluid (CSF) leak repair, and disease recurrence. Current magnetic resonance imaging (MRI) interpretation often cannot reliably differentiate CSMs, mandating adaptable intraoperative strategies. We reviewed our diagnostic and therapeutic experience after endoscopic endonasal approaches (EEAs) for CSMs.

METHODS

A retrospective record review of patients with CSM managed via EEA at the University of Southern California from 2011 to 2018 was conducted. Patient demographics, preoperative characteristics, surgical details, pathologic findings, and postoperative outcomes were assessed.

RESULTS

Analysis included 47 patients (mean age, 43.2 years); of these, 78.7% were women. Preoperative symptoms included headache (76.6%) and vision loss (42.6%). Histologically verified sellar pathology included 27 Rathke cleft cysts (RCCs) (57.4%), 17 cystic pituitary adenomas (CPAs) (36.2%), 2 arachnoid cysts (4.3%), and 1 xanthogranuloma (2.1%). Twelve patients (70.6%) with CPAs underwent complete resection and 5 (29.4%) underwent subtotal resection. All 27 patients with RCC and 2 patients with arachnoid cyst underwent complete fenestration and drainage. One xanthogranuloma was completely resected. There were 14 intraoperative (29.8%) and 4 postoperative CSF leaks (8.5%). Headaches, vision, and endocrinopathy improved in 69.2%, 80.0%, and 33.3% of patients with CPA and 73.9%, 71.4%, and 40.9% of patients with RCC, respectively. There were 2 RCC recurrences and 1 CPA recurrence over the follow-up period.

CONCLUSIONS

Surgeons must prepare for versatile management strategies of CSMs based on pretest probability associated with MRI and intraoperative findings. Outcomes after EEA for CSMs show low complication profiles and excellent rates of headache and visual improvement, albeit lower rates of endocrine normalization.

High-Field Intraoperative Magnetic Resonance Imaging Increases Extent of Resection and Progression-Free Survival for Nonfunctioning Pituitary Adenomas

BACKGROUND

The effect of intraoperative magnetic resonance imaging (iMRI) on tumor control during endoscopic transsphenoidal surgery (TSS) for nonfunctioning pituitary adenomas (NFPAs) has not yet been completely characterized. The present study assessed the effect of the iMRI findings on gross total resection (GTR) and progression-free survival at a mean follow-up of 62 ± 9.4 months.

METHODS

Retrospective analyses were performed on the data from 133 consecutive patients with NFPA who had undergone endoscopic TSS with iMRI using a 1.5T scanner.

RESULTS

Compared with the first and final iMRI scans, the GTR rate increased from 42.9% to 63.9%. Multivariate logistic regression analysis revealed that a lower GTR rate was associated with a higher Knosp score (odds ratio [OR], 3.612; 95% confidence interval [CI], 1.568-8.321; P = 0.003), an increased tumor volume (OR, 0.926; 95% CI, 0.866-0.991; P = 0.025), and a history of surgery (OR, 0.376; 95% CI, 0.155-0.917; P = 0.031). During follow-up, 8 tumors (9.4%) recurred, and 29 remnants (60.4%) regenerated. The recurrence and regeneration rates were 0.019 and 0.121 patient/year, respectively. Kaplan-Meier analysis revealed that the tumor recurrence rates were lower for patients who had undergone GTR (P < 0.01) compared with those who had not. Univariate Cox regression analysis suggested that the presence of tumor remnants (hazard ratio, 1.546; 95% CI, 1.071-2.232; P = 0.02) was the influencing factor associated with tumor progression.

CONCLUSIONS

High-field iMRI can increase the GTR rate in endoscopic TSS for NPFAs. The increased GTR rate was associated with longer progression-free survival. Cavernous sinus invasion, tumor size, and surgical history were important predictors of GTR in patients with NFPA.

Medically induced CSF rhinorrhea following treatment of macroprolactinoma: case series and literature review

PURPOSE

Although several reports have addressed cerebrospinal fluid (CSF) rhinorrhea following dopamine agonist (DA) therapy of macroprolactinomas, further study is warranted for this relatively uncommon entity. Toward this aim, our retrospective series and review of literature further clarifies recommendations in treatment of this rare problem.

METHODS

We retrospectively reviewed all macroprolactinoma cases in our hospital for a 15-year period. Our systematic search of PubMed identified original articles and reviews of all macroprolactinoma cases with an associated medication-induced CSF leak.

RESULTS

Five patients with drug-induced CSF leak were identified; four of these patients received cabergoline therapy an average of 6 weeks before the onset of rhinorrhea and then underwent surgical repair of the CSF leak. Of 35 published studies included, we identified 60 patients with medication-induced CSF leak. Medical therapy included bromocriptine in 34 patients, cabergoline in 21 patients, and use of both DAs in two patients. Three cases did include complete diagnostic and treatment data. Median time from initiation of the DA treatment to occurrence of rhinorrhea was 6 weeks. For CSF rhinorrhea, 49 patients underwent surgical repair (38 by the transnasal approach) and seven patients were treated nonoperatively.

CONCLUSION

Baseline skull base erosion in macroprolactinomas in combination with subsequent tumor shrinkage induced by DA therapy may result in spontaneous CSF rhinorrhea. Therefore, such patients should be advised about and monitored for this potential setback. Once CSF leak is diagnosed, prompt treatment must be carried out to avoid infectious complications. Transnasal surgery appears the most effective therapeutic approach.

Variability and Lack of Prognostic Value Associated With Atypical Pituitary Adenoma Diagnosis: A Systematic Review and Critical Assessment of the Diagnostic Criteria

BACKGROUND

Atypical pituitary adenomas (APAs) are a subset of pituitary adenomas (PAs) characterized by the 2004 World Health Organization (WHO) guidelines to have higher risk histopathological features than typical PAs. In July 2017, the WHO published an update to their classification of pituitary tumors and abandoned the APA terminology.

OBJECTIVE

To assess the prevalence and outcomes of patients diagnosed with APA through a literature review. Focus was placed on variation in the application of the previous WHO criteria and on rates of recurrence.

METHODS

A systematic review of PubMed (2004-July 2017) was performed to identify studies reporting prevalence and clinical characteristics/outcomes of APA. Eight studies were analyzed for prevalence. Six studies reporting histopathological details were analyzed in depth.

RESULTS

Of the 7105 included patients, 373 (5.2%) met criteria for APA (prevalence range: 3%-15%). Only 2 of 8 studies utilized identical grading criteria, demonstrating a lack of standardized application. Most APAs (84%) were macroadenomas, with 52% invasive on magnetic resonance imaging. Nonfunctional PAs were most common (37%), followed by prolactinomas (23%) and Growth Hormone adenomas (21%). Recurrence/progression occurred in 21% of APA patients (follow-up range 37-75 mo). Only 2 of 8 studies reported an association between APA diagnosis and recurrence/progression.

CONCLUSION

Based on diagnostic variability and lack of association with clinical outcomes, refinement of criteria for APA was necessary. The WHO update eliminates the ambiguity in APA diagnosis in favor of criteria that emphasize clinical behavior (invasion, recurrence, and resistance to treatment) and molecular markers. Our review supports abandonment of the previous APA designation due to limited prognostic utility.

Clinical characteristics of acromegalic patients with empty sella and their outcomes following transsphenoidal surgery

PURPOSE

To analyze the clinical characteristics of acromegalic patients with empty sella (ES, herniation of the subarachnoid space within the sella turcica) and the impact of ES on transsphenoidal surgery in such patients.

METHODS

Seventy-eight patients, newly diagnosed with acromegaly who underwent transsphenoidal surgery were included. ES was defined as the pituitary gland and adenoma occupying less than 50% of the sella turcica on midsagittal magnetic resonance (MR) imaging.

RESULTS

Twelve patients (15.4%), predominantly female (10 women, p = .047), had ES in preoperative MR imaging. ES patients had smaller mean tumor diameter (6.3 mm) than non-ES patients (11.2 mm, p = .001). In preoperative MR imaging, occult adenoma was found in three (25%) ES and three (4.5%) non-ES patients (p = .044). Intraoperative cerebrospinal fluid (CSF) leakage was more frequent in the ES patients than in the non-ES patients (58.3 vs. 25.8%, p = .024). This led to an increased rate of sellar floor reconstruction using abdominal fat and/or postoperative lumber drainage in the ES patients (ES: 41.7 vs. non-ES: 16.7%, p = .063). Endocrinological remission after surgery was more frequent in the non-ES patients (72.7%) than in the ES patients (58.3%) (p = .248).

CONCLUSIONS

Co-existence of acromegaly with ES is not rare, and is associated with occult adenoma, intra/postoperative CSF leakage, and a worse endocrinological outcome after transsphenoidal surgery; although, the underlying mechanism remains unclear.

Radiological Growth Patterns of Prolactinomas and Nonfunctioning Adenomas

Objectives: To compare growth patterns of nonfunctioning and prolactin-producing pituitary macroadenomas, and to find whether their specific growth patterns are associated with clinically significant effects on vision. Materials and Methods: From our comprehensive provincial neuropituitary registry, we retrospectively identified 35 randomly selected patients each with nonfunctioning adenomas and prolactinomas >10 mm in any dimension. MRI scans were analyzed to determine the superior and inferior growth, volume, and maximum craniocaudal height of the adenomas. Patients underwent visual field testing at diagnosis. Continuous variables were compared using Student’s t test, the Mann–Whitney U test, and ANOVA. Categorical variables were compared using the chi-square test. Results: The mean height of prolactinomas (23.2±11.3 mm) was similar to nonfunctioning adenomas (22.3±9.3 mm, p=0.8), and so were mean tumor volumes (prolactinoma=5.9±8 ml vs. nonfunctioning adenoma=4.8±5 ml, p=0.47). However, the mean suprasellar growth for prolactinomas was 2.9±5.3 mm and 7.3±4.7 mm for nonfunctioning adenomas (p<0.001), and the mean infrasellar growth was 10.2±8.0 and 5.0±6.6 mm, respectively (p=0.04). The inferior growth pattern of prolactinomas was associated with a significantly lower likelihood of having visual field abnormalities (11.4 vs. 57.1%, p<0.001). Conclusions: Prolactinomas have predominantly inferior growth compared to nonfunctioning adenomas and are less likely to cause vision changes.

Management of aggressive growth hormone secreting pituitary adenomas

Aggressive GH-secreting pituitary adenomas (GHPAs) represent an important clinical problem in patients with acromegaly. Surgical therapy, although often the mainstay of treatment for GHPAs, is less effective in aggressive GHPAs due to their invasive and destructive growth patterns, and their proclivity for infrasellar invasion. Medical therapies for GHPAs, including somatostatin analogues and GH receptor antagonists, are becoming increasingly important adjuncts to surgical intervention. Stereotactic radiosurgery serves as an important fallback therapy for tumors that cannot be cured with surgery and medications. Data suggests that patients with aggressive and refractory GHPAs are best treated at dedicated tertiary pituitary centers with multidisciplinary teams of neuroendocrinologists, neurosurgeons, radiation oncologists and other specialists who routinely provide advanced care to GHPA patients. Future research will help clarify the defining features of "aggressive" and "atypical" PAs, likely based on tumor behavior, preoperative imaging characteristics, histopathological characteristics, and molecular markers.

Epidemiology and radiological geometric assessment of pituitary macroadenomas: population-based study

CONTEXT

Pituitary adenomas are relatively common tumours with diverse clinical features. Epidemiological data are important to help quantify health burden.

OBJECTIVE

To provide in-depth epidemiological data on macroadenomas and radiologically characterize macroadenomas.

DESIGN

Population-based retrospective analysis, Prevalence as at 2014; Incidence based on data from 2000 to 2014, Retrospective analysis of baseline MRI.

SETTING

The Maltese islands.

PATIENTS

173/136 patients with macroadenomas for prevalence/incidence estimates respectively, 122 baseline MRI for radiological characterization.

MAIN OUTCOME MEASURES

Prevalence rates, Standardized Incidence rates (SIR), MRI findings.

RESULTS

The prevalence for macroadenomas was 40·67/100 000 people and the SIR was 1·90/100 000/year. Giant pituitary adenomas (>40 mm) constituted 4·8% of the whole cohort of PAs and the SIR was 0·18/100 000/year. Giant prolactinomas constituted 4·7% of all the prolactinomas and the SIR was 0·07/100 000/year, while giant NFPA constituted 6·0% of all NFPA and the SIR was 0·12/100 000/year. There was a statistically significant difference in the degree of suprasellar extension (P < 0·001) and infrasellar extension (P = 0·028) between the different macroadenoma subtypes and in the vertical extension indices (median vertical extension index NFPA 3·0 mm; PRLoma -7·7 mm; GH-secreting PA -1·7 mm; P < 0·001). Pituitary macroadenomas with cavernous sinus invasion were statistically significantly larger than those without cavernous sinus invasion (P < 0·001). NFPA had predominantly a superior extension into the cavernous sinus (63·6%) compared to the functional PAs which had predominantly an inferior extension into the cavernous sinus (59·1%) (P = 0·032).

CONCLUSIONS

The various macroadenoma subtypes' epidemiological data are presented and differences between growth patterns among the various subtypes are highlighted.

Atypical pituitary adenomas: clinical characteristics and role of ki-67 and p53 in prognostic and therapeutic evaluation. A series of 50 patients

The aim of the study was to assess incidence rate, hormonal activity, and local invasiveness and evaluate outcomes of so-diagnosed atypical pituitary adenomas that underwent endoscopic endonasal surgery at the Division of Neurosurgery of Università degli Studi di Napoli Federico II. According to the 2004 WHO classification, atypical pituitary adenomas are defined by an invasive growth, Ki-67/MIB-1 proliferative index greater than 3 %, high p53 immunoreactivity, and increased mitotic activity. A retrospective analysis of a series of 434 pituitary adenomas that underwent endoscopic endonasal surgery at our department between March 2007 and February 2013 was performed. Fifty adenomas (11.5 %) met the criteria of diagnosis of atypical lesions; 10 (21.6 %) of the 50 patients were recurrent tumors with a previous transsphenoidal surgery. Forty-one (82 %) were macroadenomas, and 21/50 (42 %) showed a clear invasion of the cavernous sinus. Histotype of atypical adenomas figured out to be nonfunctioning in 23 cases (46 %), PRL secreting in 10 cases (20 %), ACTH secreting and GH secreting each apart in 8 patients (16 %), and in a single case a GH/PRL secreting adenoma (2 %). The Ki-67 labeling index ranged from 3.5 to 22.5 % (mean 5.6 %). Tumor recurrence was observed in six cases (12 %) after a mean time of 18 months (range 9-24 months). Mean follow-up was 36.5 months (range 2-80 months). Atypical pituitary adenomas account for ca. 10 % of all pituitary adenomas; these lesions have peculiar features. It should be considered that a strong immunopositivity of p53 and higher Ki-67 LI could predict an increased risk of tumor recurrence, but more studies and larger series are expected to confirm and enlarge the diagnostic and therapeutic management process of these lesions.

Planum-Clival Angle Classification: A Novel Preoperative Evaluation for Sellar/Parasellar Surgery

Objective Endonasal approaches are increasingly used to treat sellar pathologies, leading to increased interest in achieving maximal safe resection. We propose a tool-the planum-clival angle (PCA)-and explore its surgical implications for sellar pathology resections. Design Retrospective analysis. Participants Consecutive patients with pituitary lesions between 2003 and 2013. Outcome Measures The PCA and suprasellar extension ratios; head position and extent of surgical resection. Results We enrolled 89 patients (ages 21-88 years). There were 15 type A patients (17%), 13 with suprasellar extension (89%) and ratios between 0.12 and 0.70. There were 61 type B patients (70%), 49 with suprasellar extension (81%) and ratios from 0.09 to 0.66. Finally, there were 13 type C patients (13%), 10 with suprasellar extension (73%) and ratios from 0.21 to 0.76. Type B was treated with a sphenoidectomy and neutral head positioning, type A with 10 to 20 degrees of flexion and an additional posterior ethmoidectomy with or without posterior planum resection, and type C with 10 to 20 degrees of extension and an additional superior clival resection. Conclusions Sellar anatomy and PCA influence the growth patterns of sellar lesions. Thus PCA should allow for better surgical planning and thereby improve surgical efficacy.

Clinicopathological correlates of extrasellar growth patterns in pituitary adenomas

We reviewed clinical, imaging and histopathology details of 297 patients who underwent surgery for pituitary adenomas, with an equal distribution of functional and non-functioning tumors, to examine clinicopathological correlates of extrasellar growth. Knosp grades of 3 and 4 on MRI defined cavernous sinus invasion, Hardy grades of C and D defined significant suprasellar/subfrontal extension, and intraoperative evidence of tumor eroding through the clivus or sellar floor defined infrasellar invasion. Disease status at follow-up was known in 246 patients overall, including 35 patients who were evaluated for progression of residual disease on serial imaging. On univariate analysis, we found several statistically significant associations (p < 0.05) including adenoma size with age, sex and tumor protein p53 reactivity; cavernous sinus invasion with size, non-functional status, increased mitotic activity, an elevated MIB-1 proliferation index and p53 reactivity; suprasellar/subfrontal extension with p53 reactivity; and infrasellar invasion with age and tumor size. When adjusting for confounders with logistic regression, several significant associations were evident including adenoma size with male sex and p53 reactivity; cavernous sinus invasion with size and elevated MIB-1 proliferation index; suprasellar/subfrontal extension with p53 reactivity; and infrasellar invasion with adenoma size alone. Patients with early progression of postoperative residual tumor were younger with a non-significant trend towards higher MIB-1 proliferation indices. Individual patterns of extrasellar growth in pituitary adenomas are associated with unique clinical and immunohistochemical profiles. Younger patients with elevated MIB-1 values are probably at high risk for early recurrence of non-functioning tumors. Definitions of atypia must be standardized before more robust assumptions about tumor biology can be established.

Invasion of the cavernous sinus space in pituitary adenomas: endoscopic verification and its correlation with an MRI-based classification

OBJECT An important prognostic factor for the surgical outcome and recurrence of a pituitary adenoma is its invasiveness into parasellar tissue, particularly into the space of the cavernous sinus (CS). The aims of this study were to reevaluate the existing parasellar classifications using an endoscopic technique and to evaluate the clinical and radiological outcomes associated with each grade. METHODS The authors investigated 137 pituitary macroadenomas classified radiologically at least on one side as Grade 1 or higher (parasellar extension) and correlated the surgical findings using an endoscopic technique, with special reference to the invasiveness of the tumor into the CS. In each case, postoperative MRI was performed to evaluate the gross-total resection (GTR) rate and the rate of endocrinological remission (ER) in functioning adenomas. RESULTS The authors found a 16% rate of CS invasion during surgery for these macroadenomas. Adenomas radiologically classified as Grade 1 were found to be invasive in 1.5%, and the GTR/ER rate was 83%/88%. For Grade 2 adenomas, the rate of invasion was 9.9%, and the GTR/ER rate was 71%/60%. For Grade 3 adenomas, the rate of invasion was 37.9%, and the GTR/ER rate was 75%/33%. When the superior compartment of the CS (Grade 3A) was involved, the authors found a rate of invasion that was lower (p < 0.001) than that when the inferior compartment was involved (Grade 3B). The rate of invasion in Grade 3A adenomas was 26.5% with a GTR/ER rate of 85%/67%, whereas for Grade 3B adenomas, the rate of surgically observed invasion was 70.6% with a GTR/ER rate of 64%/0%. All of the Grade 4 adenomas were invasive, and the GTR/ER rate was 0%. A comparison of microscopic and endoscopic techniques revealed no difference in adenomas with Grade 1 or 4 parasellar extension. In Grade 2 adenomas, however, the CS was found by the endoscopic technique to be invaded in 9.9% and by microscopic evaluation to be invaded in 88% (p < 0.001); in Grade 3 adenomas, the difference was 37.9% versus 86%, respectively (p = 0.002). Grade 4 adenomas had a statistically significant lower rate of GTR than those of all the other grades. In case of ER only, Grade 1 adenomas had a statistically significant higher rate of remission than did Grade 3B and Grade 4 adenomas. CONCLUSIONS The proposed classification proved that with increasing grades, the likelihood of surgically observed invasion rises and the chance of GTR and ER decreases. The direct endoscopic view confirmed the low rate of invasion of Grade 1 adenomas but showed significantly lower rates of invasion in Grade 2 and 3 adenomas than those previously found using the microscopic technique. In cases in which the intracavernous internal carotid artery was encased (Grade 4), all the adenomas were invasive and the GTR/ER rate was 0%/0%. The authors suggest the addition of Grades 3A and 3B to distinguish the strikingly different outcomes of adenomas invading the superior CS compartments and those invading the inferior CS compartments.

Indicators of a Reduced Intercarotid Artery Distance in Patients Undergoing Endoscopic Transsphenoidal Surgery

Objective To identify clinicopathologic factors associated with a reduced intercarotid distance (ICD) and subgroups at risk for internal carotid artery injury during transsphenoidal surgery. Design A retrospective case-control study. Setting This study was conducted at the McGill University Health Centre, a university-affiliated tertiary care center. Participants Patients with a sellar or parasellar tumor and nontumor controls were included in the study. Main Outcome Measures The smallest distance between the internal carotid arteries at the clival, cavernous, and paraclinoid segments on coronal magnetic resonance imaging was measured. Demographic profiles, cephalometric measurements, tumor dimensions, and sphenoid configuration were assessed as potential determinants of the ICD. Results A total of 212 cases and 34 controls were analyzed. Widening of the ICD at the three segments of the internal carotid arteries was found in patients with pituitary macroadenomas (p < 0.01). Patients with a growth hormone-secreting adenoma had a markedly reduced ICD at the clivus compared with controls (1.59 cm versus 1.77 cm; p = 0.02; 95% confidence interval [CI], 0.03-0.32). The paraclinoid ICD was reduced in patients with an anterior fossa meningioma (1.24 cm versus 1.33 cm; p = 0.04; 95% CI, 0.01-0.45). Conclusion Identifying clinicopathologic factors affecting the ICD can help surgeons recognize constraints to endoscopic access of the skull base and avoid inadvertent arterial injury.

Growth hormone secreting pituitary microadenomas and empty sella - An under-recognized association?

OBJECTIVE

To describe an association of growth hormone (GH) secreting pituitary microadenomas and empty sella (ES), which has been described in case reports - the underlying mechanisms are unclear.

METHODS

We retrospectively analyzed patients operated for GH-producing pituitary adenomas between February 2004 and February 2009. Magnetic resonance imaging (MRI), computed tomography (CT) imaging, and pituitary function testing were performed. All cases underwent transsphenoidal surgery (TSS). Mean follow up was 38 months (range 12-80 months).

RESULTS

Out of 152 patients with acromegaly due to GH-producing pituitary adenomas (female:male=73:79; age range 17-63 years), 69 patients had microadenomas (45.4%; 38 females, 31 males). We found 14 cases (14/69, 20.3%), all microadenomas, with presurgical evidence of ES - 10 females (71%) and 4 males (29%) (female:male=2.5:1). When compared with 103 patients with GH-negative microadenomas treated in the same time period (ES in 4 of 103; 3.9%), ES was highly significantly associated with GH production by the microadenoma (p=0.001). In acromegalics with empty sella, no cases of ectopic adenoma were found. Postoperatively, GH and IGF-1 levels fell in all patients, and 7 cases had random GH and IGF-1 levels consistent with cure.

CONCLUSION

The combination of GH-producing microadenomas and empty, enlarged sella is not rare. In this setting, preoperative CT scans are very useful and the transsphenoidal approach is efficient and safe. The mechanism underlying the association of GH-producing microadenomas and empty sella remains unclear and requires further studies.

Growth patterns of pituitary adenomas and histopathological correlates

CONTEXT

The factors associated with pituitary adenoma (PA) growth rate remain unclear.

OBJECTIVE

The objective of the study was to establish whether the preoperative growth and extension pattern of PA can predict postoperative growth rate and recurrence in addition to whether the PA growth rate correlates with proliferation and growth factor expression.

PATIENTS

One hundred fifty-three consecutive patients who underwent surgery for pituitary adenoma from 1999 to 2011 at Toronto Western Hospital were identified.

MAIN OUTCOME MEASURES

The PA growth rate was measured both pre- and postoperatively, and its association with patient demographics, magnetic resonance imaging, and histolopathological parameters was determined.

RESULTS

The preoperative growth rate was associated with age (P = .0001), suprasellar growth (P = .003), the presence of a cyst/hemorrhage (P = .004), the mindbomb homolog-1 (P = .005), fibroblast growth factor receptor-4 positivity (P = .047), and p27 negativity (P = .007). After surgery, there were 34.6% residual volumes, which were associated with older age (P = .038) and also with growth patterns including anterior, posterior, suprasellar, and cavernous sinus extension (P = .001); 43.3% of these residuals grew and postoperative growth rate was calculated. Pre- and postoperative growth rates were correlated (r = 0.497, P = .026). Postoperative growth rate was associated with age (P = .015) and gender (P = .017).

CONCLUSIONS

Our data suggest that the growth rate of PAs are influenced by various patient- and tumor-specific characteristics including the age and sex of the patient, the specific subtype of PA, its hormonal activity, its immunohistochemical profile including the mindbomb homolog 1 labeling index status, and its preponderance for different growth directions relative to the pituitary fossa. Furthermore, the pre- and postoperative PA growth rates were correlated, suggesting that postoperative PA growth rates can be predicted, in part, by preoperative growth rates, thus better informing postoperative outcome.

Geometric survey on magnetic resonance imaging of growth hormone producing pituitary adenoma

Apart from the radiologic features regarding size and invasiveness, we had noticed some differences in morphology among types of pituitary adenomas. We conducted this study to verify the differences in radiologic morphology between growth hormone producing pituitary adenomas (GHoma) and nonfunctioning pituitary adenomas (NFoma). Pre-surgical magnetic resonance images (MRIs) were assessed in 50 cases of GHoma and 50 cases of NFoma. Geometric parameters on MRI were set in accordance with sellar anatomy. Intensity of T1-weighted image was not different between the two groups, but hypo-intensity of T2-weighted image was more frequently seen in GHoma. Predominant inferior extension of tumor was seen mostly in GHoma (88 vs. 38%). Extension of the tumor to the superior compartment of cavernous sinus was more frequent in NFoma. Pituitary gland was generally located superior to GHoma and postero-superior to NFoma. Growth characteristics of pituitary adenoma were confirmed to differ between GHoma and NFoma.

The "extended" endoscopic endonasal approach for the removal of a mixed intrasuprasellar germinoma: Technical case report

Background:

Intracranial germ cell tumors (GCTs) represent less than 5% of pediatric brain tumors. Neurosurgical treatment remains essential in the management of patients with intracranial nongerminomatous GCT.

Case Description:

A 12-year-old girl presented with clinical features of neurohypophyseal dysfunction and rapidly progressive visual worsening. Magnetic resonance imaging (MRI) showed a lesion arising from the sella with a significant suprasellar component, compressing the optic chiasm and extending into the third ventricle. The tumor was removed via an endoscopic endonasal transtuberculum-transplanum approach and the histology revealed a mixed germinoma. In the postoperative course, a conspicuous improvement of visual function was observed; an early postoperative MRI showed near-total removal of the lesion. The patient was referred to pediatric oncologist for the adjunctive chemotherapy and radiotherapy.

Conclusions:

The management of primary intracranial sellar and suprasellar germinomas still remains controversial. With this report we highlighted another possible surgical option among therapeutic strategies for these highly malignant tumors.

Severe growth hormone deficiency is rare in surgically-cured acromegalics

Growth hormone deficiency (GHD) in surgically-cured acromegalics has been reported to negatively affect their metabolic condition and quality of life (QOL). The incidence of GHD, its causes, and its effects on their physio-psychological condition remain to be examined in detail. We performed a retrospective study to investigate GH secretory function in surgically-cured acromegalics, prognostic factors of GHD, and its impact on QOL. The study population consisted of 72 acromegalics who were determined to be surgically cured according to the Cortina consensus criteria. We recorded the incidence of impaired GH secretory function based on the peak GH level during postoperative insulin tolerance test (ITT) which lowered their nadir blood sugar to under 50 mg/dL. Their QOL was evaluated by SF-36. In surgically-cured acromegalics, the incidence of severe GHD (peak GH during ITT ≦ 3.0 μg/L) was 12.5 % (9/72). The preoperative tumor size was significantly larger in patients with severe GHD than without severe GHD (21.9 ± 9.0 vs. 15.5 ± 7.1 mm, p = 0.017). The peak GH levels during postoperative ITT were statistically correlated with the physical but not the mental component summary of the SF-36 score. The incidence of GHD was 12.5 % in our surgically-cured acromegalics. As some QOL aspects are positively related with peak GH levels during postoperative ITT, efforts should be made to preserve pituitary function in acromegalic patients undergoing adenomectomy.

Sphenoid sinus anatomy and suprasellar extension of pituitary tumors

OBJECT

As tumors enlarge, they generally grow along paths of least resistance. For pituitary macroadenomas, extrasellar extension into the suprasellar region, cavernous sinus, or sphenoid sinus may occur. The sphenoid sinus is known to have a variable anatomical configuration, and the authors hypothesize that certain anatomical factors may resist tumor expansion into the sphenoid sinus, thereby directing tumor growth into the suprasellar space. In this paper the authors' goal was to determine if sphenoid anatomy influences pituitary tumor growth.

METHODS

The authors conducted a retrospective analysis of 106 consecutive surgical cases of pituitary macroadenoma. Patient demographics, suprasellar extension, sellar width, and features of the sphenoid intersinus septum were recorded on radiographic review. The chi-square test, t-test, logistic regression, and classification and regression tree analysis were used for statistical analysis.

RESULTS

Of the 106 patients included in the study, 71 (67%) demonstrated suprasellar extension of their tumor. Patients with suprasellar tumor extension had significantly greater intersinus septum width (width > 1.27 mm: OR = 14.32; p = 0.0012) and were significantly older (age > 54 yrs: OR = 3.33; p = 0.0176). They also tended to be male and to have two or more sphenoid partitions (OR = 6.58; p = 0.0306). While patients with suprasellar extension tended to be more likely to have a midline partition and a larger sellar width than their counterparts, these differences did not reach statistical significance.

CONCLUSIONS

Certain aspects of the sphenoid sinus anatomy may function to resist pituitary tumor growth into the sphenoid sinus. Progressive enlargement of pituitary macroadenomas may extend in a suprasellar direction, in part, as a consequence of the sphenoid sinus anatomy.

Spontaneous and medically induced cerebrospinal fluid leakage in the setting of pituitary adenomas: review of the literature

OBJECT

Spontaneous and medically induced CSF leaks are uncommonly associated with pituitary adenomas. The aim of this study was to further characterize the clinical scenarios most closely associated with this phenomenon.

METHODS

A review of the literature was conducted to identify all cases of nonsurgical CSF leaks associated with pituitary adenomas. The authors aimed to identify associated risk factors and management strategies used to treat these tumors and repair the CSF leak site.

RESULTS

Fifty-two patients with spontaneous or medically induced CSF leaks in the setting of a pituitary adenoma were identified from 29 articles published from 1980 through 2011. In 38 patients (73%), CSF rhinorrhea developed following initiation of medical therapy, whereas spontaneous CSF leakage developed as the presenting symptom in 14 patients (27%). The patients' mean age was 42.8 years (range 23-68 years). There were 35 males and 17 females. Forty-two patients (81%) had a prolactinoma, with the remaining patients having the following tumors: nonfunctioning pituitary adenoma (6 patients), growth hormone-secreting adenoma (2 patients), mammosomatotroph cell adenoma (1 patient), and ACTH-secreting adenoma (1 patient). Infrasellar tumor invasion into the paranasal sinuses was specifically reported in 56% of patients. The medical agents associated with CSF leakage were dopamine agonists (97%) and somatostatin analogs (3%). The average time from initialization of medical treatment to onset of rhinorrhea was 3.3 months (range 3 days-17 months). Nonsurgical management was successful in 4 patients, including 1 who had successful resolution with a temporary lumbar drain. Forty-six patients (88%) underwent surgical intervention to treat the CSF leak and/or resect the tumor. In 2 patients, surgery was not performed due to medical contraindications or patient preference.

CONCLUSIONS

Nonsurgical development of CSF rhinorrhea may occur in the setting of pituitary adenomas, especially following favorable response of invasive prolactinomas to initiation of dopamine agonist therapy. Additional cases have been reported as the presenting symptom of a pituitary adenoma and are likely to be related to decreased tumor volume due to intrinsic infarction or hemorrhage, ongoing invasion, and/or increases in intracranial pressure. Surgical repair, preferentially via a transsphenoidal approach, is the recommended initial treatment for definitive repair of the CSF leak and achievement of maximal tumor resection.

Prevention of intraoperative cerebrospinal fluid leaks by lumbar cerebrospinal fluid drainage during surgery for pituitary macroadenomas

OBJECT

Cerebrospinal fluid leakage is a major complication of transsphenoidal surgery. An intraoperative CSF leak, which occurs in up to 50% of pituitary tumor cases, is the only modifiable risk factor for postoperative leaks. Although several techniques have been described for surgical repair when an intraoperative leak is noted, none has been proposed to prevent an intraoperative CSF leak. The authors postulated that intraoperative CSF drainage would diminish tension on the arachnoid, decrease the rate of intraoperative CSF leakage during surgery for larger tumors, and reduce the need for surgical repair of CSF leaks.

METHODS

The results of 114 transsphenoidal operations for pituitary macroadenoma performed without intraoperative CSF drainage were compared with the findings from 44 cases in which a lumbar subarachnoid catheter was placed before surgery to drain CSF at the time of dural exposure and tumor removal.

RESULTS

Cerebrospinal fluid drainage reduced the rate of intraoperative CSF leakage from 41% to 5% (p < 0.001). This reduction occurred in macroadenomas with (from 57% to 5%, p < 0.001) and those without suprasellar extension (from 29% to 0%, p = 0.31). The rate of postoperative CSF leakage was similar (5% vs 5%), despite the fact that intraoperative CSF drainage reduced the need for operative repair (from 32% to 5%, p < 0.001). There were no significant catheter-related complications.

CONCLUSIONS

Cerebrospinal fluid drainage during transsphenoidal surgery for macroadenomas reduces the rate of intraoperative CSF leaks. This preventative measure obviated the need for surgical repair of intraoperative CSF leaks using autologous fat graft placement, other operative techniques, postoperative lumbar drainage, and/or reoperation in most patients and is associated with minimal risks.

Expression of cyclooxygenase-2 (COX-2) in pituitary tumours

BACKGROUND

Microvessel density in angiogenesis is regarded as a prognostic factor of tumour invasiveness, independent of cell proliferation. In recent studies of pituitary tumours, correlation between the expression of cyclooxygenase-2 (COX-2) and micro-vascularization density and microvessel surface density has been established. We studied the expression of COX-2 in different types of pituitary adenomas to determine the usefulness of COX-2 expression as a prognostic factor of tumour progression or recurrence in patients with hypophyseal tumours.

MATERIAL/METHODS

We retrospectively studied a group of 60 patients of mean age 46.7±17.6 (range, 18 to 85) years who underwent pituitary tumour surgery. Expression of COX-2, as determined by immunohistochemistry, was analyzed in relation to histopathology features of tumour, clinical symptoms, MR imaging and post-operative recurrence/progression of disease.

RESULTS

COX-2 was expressed in adenomas of 87% of patients, with a median index value of 57.5% [IQR=60.5]. Highest COX-2 expression was observed in hormonally inactive adenomas and gonadotropinomas and lowest in prolactinomas. We found no differences in COX-2 expression with respect to patient age, gender, tumour size, degree of tumour invasiveness, or whether tumours were immunopositive or immunonegative for pituitary hormones, nor have we found any relation between COX-2 expression and recurrence or progression of tumour size.

CONCLUSIONS

COX-2 does not appear to be a predictive factor for recurrence or progression of tumour size. Nevertheless, due to the observed relatively high expression of COX-2 in pituitary adenomas, further studies with COX-2 inhibitors are justified in these tumours.

Surgery and radiosurgery for acromegaly: a review of indications, operative techniques, outcomes, and complications

Among multimodality treatments for acromegaly, the goals of surgical intervention are to balance maximal tumor resection while preserving normal pituitary function and maintaining patient safety. The resection of growth hormone-(GH-) secreting pituitary adenomas in the hands of experienced surgeons results in hormonal remission in 50-70% of patients. Acromegalic patients often have medical comorbidities and anatomical variations complicating anesthesia and surgical management. Despite these challenges, complications such as CSF leak or new hypopituitarism following surgery remain uncommon. Over the past decade, endoscopic approaches to pituitary tumors have improved visualization and facilitated identification of additional tumor using angled telescopes. Patients with persistent acromegaly following surgery require continued medical and/or radiation-based interventions. The adjunctive use of stereotactic radiosurgery offers hormonal remission in 40-50% of patients. In this article, the current preoperative evaluation, indications for surgery, surgical approaches, role of radiosurgery, complications, and remission criteria following operative resection of GH adenomas are reviewed.

The neurosurgical anatomy of the sphenoid sinus and sellar floor in endoscopic transsphenoidal surgery

OBJECT

A considerable degree of variability exists in the anatomy of the sphenoid sinus, sella turcica, and surrounding skull base structures. The authors aimed to characterize neuroimaging and intraoperative variations in the sagittal and coronal surgical anatomy of healthy controls and patients with sellar lesions.

METHODS

Magnetic resonance imaging studies obtained in 100 healthy adults and 78 patients with sellar lesions were reviewed. The following measurements were made on midline sagittal images: sellar face, sellar prominence, sellar angle, tuberculum sellae angle, sellar-clival angle, length of planum sphenoidale, and length of clivus. The septal configuration of the sphenoid sinus was classified as either simple or complex, according to the number of septa, their symmetry, and their morphological features. The following measurements were made on coronal images: maximum width of the sphenoid sinus and sellar face, and the distance between the parasellar and midclivus internal carotid arteries. Neuroimaging results were correlated with intraoperative findings during endoscopic transsphenoidal surgery.

RESULTS

Three sellar floor morphologies were defined in normal adults: prominent (sellar angle of < 90°) in 25%, curved (sellar angle 90-150°) in 63%, flat (sellar angle > 150°) in 11%, and no floor (conchal sphenoid) in 1%. In healthy adults, the following mean measurements were obtained: sellar face, 13.4 mm; sellar prominence, 3.0 mm; sellar angle, 112°; angle of tuberculum sellae, 112°; and sellar-clival angle, 117°. Compared with healthy adults, patients with sellar lesions were more likely to have prominent sellar types (43% vs 25%, p = 0.01), a more acute sellar angle (102° vs 112°, p = 0.03), a more prominent sellar floor (3.8 vs 3.0 mm, p < 0.005), and more acute tuberculum (105° vs 112°, p < 0.01) and sellar-clival (105° vs 117°, p < 0.003) angles. A flat sellar floor was more difficult to identify intraoperatively and more likely to require the use of a chisel or drill to expose (75% vs 25%, p = 0.01). A simple sphenoid sinus configuration (no septa, 1 vertical septum, or 2 symmetric vertical septa) was noted in 71% of studies, and the other 29% showed a complex configuration (2 or more asymmetrical septa, 3 or more septa of any kind, or the presence of a horizontal septum). Intraoperative correlation was more challenging in cases with complex sinus anatomy; the most reliable intraoperative midline markers were the vomer, superior sphenoid rostrum, and bilateral parasellar and clival carotid protuberances.

CONCLUSIONS

Preoperative assessment of neuroimaging studies is critical for characterizing the morphological characteristics of the sphenoid sinus, sellar floor, tuberculum sellae, and clivus. The flat sellar type identified in 11% of people) or a complex sphenoid sinus configuration (in 29% of people) may make intraoperative correlation substantially more challenging. An understanding of the regional anatomy and its variability can improve the safety and accuracy of transsphenoidal and extended endoscopic skull base approaches.