The Clinicopathological Spectrum of Acromegaly

Effectiveness of combined first-line medical treatment in acromegaly with prolactin cosecretion

OBJECTIVE

The aim of this study is to compare the response to first-line medical treatment in treatment-naive acromegaly patients with pure growth hormone (GH)-secreting pituitary adenoma (GH-PA) and those with GH and prolactin cosecreting PA (GH&PRL-PA).

DESIGN

This is a retrospective multicentric study of acromegaly patients followed from 2003 to 2023 in 33 tertiary Spanish hospitals with at least 6 months of first-line medical treatment.

METHODS

Baseline characteristics, first-line medical treatment strategies, and outcomes were analyzed. We employed a multiple logistic regression full model to estimate the impact of some baseline characteristics on disease control after each treatment modality.

RESULTS

Of the 144 patients included, 72.9% had a GH-PA, and 27.1% had a GH&PRL-PA. Patients with GH&PRL-PA were younger (43.9 ± 15.0 vs 51.9 ± 12.7 years, P < .01) and harboring more frequently macroadenomas (89.7% vs 72.1%, P = .03). First-generation somatostatin receptor ligand (fgSRL) as monotherapy was given to 106 (73.6%) and a combination treatment with fgSRL and cabergoline in the remaining 38 (26.4%). Patients with GH&PRL-PA received more frequently a combination therapy (56.4% vs 15.2%, P < .01). After 6 months of treatment, in the group of patients under fgSRL as monotherapy, those patients with GH&PRL-PA had worse control compared to GH-PAs (29.4% vs 55.1%, P = .04). However, these differences in the rate of disease control between both groups disappeared when both received combination treatment with fgSRL and cabergoline.

CONCLUSION

In GH&PRL-PA, the biochemical control achieved with fgSRL as monotherapy is substantially worse than in patients harboring GH-PA, supporting the inclusion of cabergoline as first-line medical treatment in combination with fgSRLs in these subgroups of patients.

Pathologic Characteristics of Somatotroph Pituitary Tumors-An Observational Single-Center Study

The pathologic evaluation of a tumor tissue is an essential part of an acromegaly patient's assessment. This study aimed to analyze the pathologic characteristics of pituitary tumors in patients with acromegaly. The demographic data, in addition to the hormonal, imaging, and pathologic results of 120 patients with acromegaly after pituitary surgery, were extracted from the Polish Acromegaly Registry. We compared sparsely and densely granulated tumors, GH(+), mixed GH(+)/PRL(+) and plurihormonal tumors, α-subunit-positive and α-subunit-negative tumors, and tumors of various Ki-67 indices in terms of the abovementioned features. Sparsely granulated tumors were more frequent in women than in men (p = 0.001) and in younger patients (p = 0.011), and they were larger (p < 0.001) compared to densely granulated tumors. Tumors with positive α-subunit were smaller (p = 0.013), showed extrasellar extension less often (p = 0.039), and were more often densely granulated (p < 0.001) compared to α-subunit-negative tumors. Patients with a higher Ki-67 index were younger (p < 0.001) and more often diagnosed with genetic syndromes (p = 0.02); they had higher GH concentrations (p = 0.007), larger tumors (p = 0.006), and cavernous sinus invasions more frequently (p = 0.022). Conclusions: The pathologic characteristics of somatotroph pituitary tumors are associated with patient's age, sex, hormonal results, tumor size, and the degree of extrasellar expansion.

Ectopic Hormonal Syndromes: Cushing's Syndrome and Acromegaly

Ectopic hormone production may be present in neuroendocrine and non-endocrine neoplasms. Ectopic sources of growth hormone, adrenocorticotropin (ACTH), or their releasing factors are uncommon but clinically relevant. Ectopic ACTH tumors have been studied more than the rest, but there are still no comprehensive multidisciplinary guidelines that include all the pitfalls in the diagnosis and management of ectopic hormonal syndromes and the neoplasms associated with ectopic Cushing or acromegaly. The frequency of neuroendocrine neoplasms and other neoplasms with neuroendocrine differentiation has been increasing in recent decades. The review of the available data on these tumors, their classification, and improvements in diagnostic and therapeutic procedures is important to understand the relevance of ectopic Cushing's syndrome and acromegaly in clinical practice.

Position statement on the diagnosis and management of acromegaly: The French National Diagnosis and Treatment Protocol (NDTP)

Acromegaly is a rare disease with prevalence of approximately 60 cases per million, slight female predominance and peak onset in adults in the fourth decade. Clinical diagnosis is often delayed by several years due to the slowly progressive onset of symptoms. There are multiple clinical criteria that define acromegaly: dysmorphic syndrome of insidious onset, symptoms related to the pituitary tumor (headaches, visual disorders), general signs (sweating, carpal tunnel syndrome, joint pain, etc.), complications of the disease (musculoskeletal, cardiovascular, pneumological, dental, metabolic comorbidities, thyroid nodules, colonic polyps, etc.) or sometimes clinical signs of associated prolactin hypersecretion (erectile dysfunction in men or cycle disorder in women) or concomitant mass-induced hypopituitarism (fatigue and other symptoms related to pituitary hormone deficiencies). Biological confirmation is based initially on elevated IGF-I and lack of GH suppression on oral glucose tolerance test or an elevated mean GH on repeated measurements. In confirmed cases, imaging by pituitary MRI identifies the causal tumor, to best determine management. In a minority of cases, acromegaly can be linked to a genetic predisposition, especially when it occurs at a young age or in a familial context. The first-line treatment is most often surgical removal of the somatotroph pituitary tumor, either immediately or after transient medical treatment. Medical treatments are most often proposed in patients not controlled by surgical removal. Conformal or stereotactic radiotherapy may be discussed on a case-by-case basis, especially in case of drug inefficacy or poor tolerance. Acromegaly should be managed by a multidisciplinary team, preferably within an expert center such as a reference or skill center for rare pituitary diseases.

DNA Methylation Pattern in Somatotroph Pituitary Neuroendocrine Tumors

INTRODUCTION

Growth hormone secretion by sporadic somatotroph neuroendocrine pituitary tumors (PitNETs) is a major cause of acromegaly. These tumors are relatively heterogenous in terms of histopathological and molecular features. Our previous transcriptomic profiling of somatotroph tumors revealed three distinct molecular subtypes. This study aimed to investigate the difference in DNA methylation patterns in subtypes of somatotroph PitNETs and its role in distinctive gene expression.

METHODS

Genome-wide DNA methylation was investigated in 48 somatotroph PitNETs with EPIC microarrays. Gene expression was assessed with RNAseq. Bisulfite pyrosequencing and qRT-PCR were used for verifying the results of DNA methylation and gene expression.

RESULTS

Clustering tumor samples based on methylation data reflected the transcriptome-related classification. Subtype 1 tumors are densely granulated without GNAS mutation, characterized by high expression of NR5A1 (SF-1) and GIPR. The expression of both genes is correlated with specific methylation of the gene body and promoter. This subtype has a lower methylation level of 5' gene regions and CpG islands than the remaining tumors. Subtype 2 PitNETs are densely granulated and frequently GNAS-mutated, while those in subtype 3 are mainly sparsely granulated. Methylation/expression analysis indicates that ∼50% genes located in differentially methylated regions are those differentially expressed between tumor subtypes. Correlation analysis revealed DNA methylation-controlled genes, including CDKN1B, CCND2, EBF3, CDH4, CDH12, MGMT, STAT5A, PLXND1, PTPRE, and MMP16, and genes encoding ion channels and semaphorins.

CONCLUSION

DNA methylation profiling confirmed the existence of three molecular subtypes of somatotroph PitNETs. High expression of NR5A1 and GIPR in subtype 1 tumors is correlated with specific methylation of both genes.

Prolactin and Growth Hormone Signaling and Interlink Focused on the Mammosomatotroph Paradigm: A Comprehensive Review of the Literature

Prolactin (PRL) and growth hormone (GH) are peptide hormones that bind to the class 1 cytokine receptor superfamily, a highly conserved cell surface class of receptors. Both hormones control their own secretion via a negative autocrine loop in their own mammosomatotroph, lactotroph or somatotroph. In this regard, GH and PRL are regulated by similar signaling pathways involving cell growth and hormone secretion. Thus, GH and PRL dysregulation and pituitary neuroendocrine tumor (PitNET) development may have common pathogenic pathways. Based on cell linage, lactotroph and somatotroph PitNETs come from pituitary-specific POU-class homeodomain transcription factor (Pit-1). Mammosomatotroph and plurihormonal PitNETs are a unique subtype of PitNETs that arise from a single-cell population of Pit-1 lineage. In contrast, mixed somatotroph-lactotroph PitNETs are composed of two distinct cell populations: somatotrophs and lactotrophs. Morphologic features that distinguish indolent PitNETs from locally aggressive ones are still unidentified, and no single prognostic parameter can predict tumor aggressiveness or treatment response. In this review, we aim to explore the latest research on lactotroph and somatotroph PitNETs, the molecular mechanisms involved in PRL and GH axis regulation and the signaling pathways involved in their aggressiveness, particularly focused on mammosomatotroph and mixed subtypes. Finally, we summarize epidemiological, clinical, and radiological features of these exceptional tumors. We aim to shed light, from basic to clinical settings, on new perspectives and scientific gaps in this field.

Comparative effectiveness of endoscopic and microscopic adenoma removal in acromegaly

Introduction

Somatotropinomas are the main cause of acromegaly. Surgery is the primary and most efficient method of treatment. The study aimed to compare the radicality of small-sized and medium (<30 mm) somatotropinoma removal and the incidence of postoperative complications in patients with acromegaly when using microscopic and endoscopic techniques.

Methods

In this randomized controlled trial, a total of 83 patients with acromegaly underwent transspheroidal endoscopy or microscopic surgery. Somatotropinoma was the cause of acromegaly in all cases. Patients were randomly divided into two comparison groups depending on the applied surgical technique. Group 1 (n = 40) consisted of patients who underwent adenomectomy with transnasal transsphenoidal access by a microscope. Group 2 (n = 43) included patients who underwent the same surgical procedure with an endoscope. The following indicators were assessed: radicality of tumor removal, treatment effectiveness, postoperative complications, and remission rate.

Results

The study has shown that removal of somatotropinoma in patients with acromegaly using endoscopic technique increases the radicality of tumor removal in comparison with microscopic technique. Total removal of somatotropinoma was successful in 88.4% of cases when using the endoscopic technique. Secondly, the segmentation of patients according to their tumor characteristics poses challenges, primarily owing to the rarity of acromegaly as a disease. The difference between groups was not statistically significant (p=1.02). There were no statistically significant differences in basal GH level and IGF-1 level between groups (p=0.546 and p=0.784, respectively).

Discussion

Endonasal transsphenoidal endoscopic adenomectomy is proven efficacy, a less traumatic degree, and higher somatotropinoma removal radicality. Both surgical methods lead to disease remission.

Acromegaly: Pathophysiological Considerations and Treatment Options Including the Evolving Role of Oral Somatostatin Analogs

Acromegaly is a condition most commonly diagnosed in the fifth decade of life and has numerous treatment options. In this regard, Mycapssa® is the first FDA-approved oral octreotide capsule for treating acromegaly, combining the efficacy of the somatostatin receptor ligand, octreotide, with the ease of a twice-daily oral capsule. Where surgical treatment is not an option, somatostatin analogs, including octreotide, are the first line of medical treatment for acromegaly, requiring regular subcutaneous or intramuscular injections administered by a patient's healthcare provider. Octreotide capsules (Mycapssa®) provide an alternative to these somatostatin receptor ligand injections by combining octreotide with other excipients to produce a transient permeability enhancer technology that improves paracellular transport of octreotide across the gastrointestinal wall into the small intestine. Across multiple trials, including open-label (CH-ACM-01), double-blind placebo-controlled (CHIASMA OPTIMAL), and open-label extension of the trial period (CHIASMA OPTIMAL OLE), Mycapssa® octreotide capsules maintained a consistent biochemical normalization of IGF-1 and GH levels, safety profiles similar to injected somatostatin receptor ligands, and patient preference to continued treatment with octreotide capsules. While clinical trial data supports the use of octreotide capsules (Mycapssa®) in the pharmacological management of GH and IGF-1 levels, very little data exist regarding the drug's efficacy, tolerability, and use in female or pediatric-specific populations. A better understanding of the efficacy, application, and role of oral octreotide capsules in the long-term medical management of acromegaly in a diversity of populations is imperative to best determine the risks/benefits for the clinician.

A Rare Association of Pituitary Macroadenoma With Nasopharyngeal Angiofibroma: A Case Report

Pituitary macroadenoma and angiofibroma are two distinct and diverse types of tumors that can develop in different anatomical locations and clinical characteristics and are not typically related to each other in terms of their hormonal or developmental aspects. This case describes an adult male with pituitary macroadenoma with nasal angiofibroma. A 35-year-old male was diagnosed with pituitary macroadenoma and incidentally found to have juvenile nasopharyngeal angiofibroma (NPA). The patient underwent a diagnostic workup, including imaging studies and hormonal assays, which confirmed the concomitant presence of both tumors. The patient underwent successful endoscopic surgical excision of the NPA and transnasal transsphenoidal endoscopic pituitary macroadenoma excision as a two-stage operation. The patient was followed up postoperatively and had no evidence of tumor recurrence or hormonal imbalances. The importance of complete and comprehensive diagnostic workup and multidisciplinary management in achieving successful and optimum treatment outcomes for coexisting NPA and pituitary macroadenoma in an adult patient is highlighted in the present report.

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.

Delving into Acromegaly

Acromegaly is a rare and disabling disease with some distinct and striking clinical features that have fascinated (and frightened) laypeople and medical experts alike throughout history [...].

An Overview of Pituitary Neuroendocrine Tumors (PitNET) and Algorithmic Approach to Diagnosis

The diagnostic algorithm and nomenclature of pituitary neuroendocrine tumors have evolved over the past decade, beginning with simpler categorical schemes focused on histomorphologic features and moving to a more sophisticated lineage-specific categorization. This contemporary overview highlights a multimodal approach to pituitary neuroendocrine tumors with a focus on changes in nomenclature, classification, and subclassification; including, brief comments on treatment, and new guidelines for genetic screening, particularly for young patients with such neoplasms.

Transcriptomic Classification of Pituitary Neuroendocrine Tumors Causing Acromegaly

Acromegaly results from growth hormone hypersecretion, predominantly caused by a somatotroph pituitary neuroendocrine tumor (PitNET). Acromegaly-causing tumors are histologically diverse. Our aim was to determine transcriptomic profiles of various somatotroph PitNETs and to evaluate clinical implication of differential gene expression. A total of 48 tumors were subjected to RNA sequencing, while expression of selected genes was assessed in 134 tumors with qRT-PCR. Whole-transcriptome analysis revealed three transcriptomic groups of somatotroph PitNETs. They differ in expression of numerous genes including those involved in growth hormone secretion and known prognostic genes. Transcriptomic subgroups can be distinguished by determining the expression of marker genes. Analysis of the entire cohort of patients confirmed differences between molecular subtypes of tumors. Transcriptomic group 1 includes ~20% of acromegaly patients with GNAS mutations-negative, mainly densely granulated tumors that co-express GIPR and NR5A1 (SF-1). SF-1 expression was verified with immunohistochemistry. Transcriptomic group 2 tumors are the most common (46%) and include mainly GNAS-mutated, densely granulated somatotroph and mixed PitNETs. They have a smaller size and express favorable prognosis-related genes. Transcriptomic group 3 includes predominantly sparsely granulated somatotroph PitNETs with low GNAS mutations frequency causing ~35% of acromegaly. Ghrelin signaling is implicated in their pathogenesis. They have an unfavorable gene expression profile and higher invasive growth rate.

Corneal Tonometric and Morphological Changes in Patients with Acromegaly

(1) Purpose: This study aimed to investigate the changes in Reichert Ocular Response Analyzer (ORA) parameters, corneal endothelium parameters, central corneal thickness (CCT), and intraocular pressure (IOP) before and after the transsphenoidal resection of pituitary adenoma in patients with acromegaly. (2) Methods: This was a single-center, prospective, interventional study. Twenty patients with newly diagnosed acromegaly were examined before and 19 ± 9 months after transsphenoidal resection. The participants underwent a comprehensive ophthalmological examination including pneumatic IOP (IOP air puff), Goldmann applanation tonometry (IOP GAT), CCT measured using the iPac pachymeter (CCT_UP), IOP value corrected for CCT_UP using the Ehlers formula (IOPc) ORA measurements included corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated IOP (IOPcc), and Goldmann-correlated IOP (IOPg). CCT from non-contact specular microscopy (CCT_NSM), the number of endothelial cells (CD) per mm2, and average cell size (AVG) were determined with non-contact specular microscopy. (3) Results: A statistically significant decrease was observed in CCT_UP (p = 0.007), and IOP air puff (p = 0.012) after surgery. Moreover, we noted a statistically significant increase in CD (p = 0.001), and a statistically significant decrease in AVG (p = 0.009) and CCT_NSM (p = 0.004) after surgery. A statistically significant decrease was also observed in IOPg (p = 0.011), CH (p = 0.016), and CRF (p = 0.001) after surgery. The mean value of IOP GAT and IOPc was lower after the surgery. However, the difference was not statistically significant. (4) Conclusions: Our study revealed significant changes in biomechanics, corneal endothelium, CCT and IOP after pituitary adenoma resection in patients with acromegaly. It proves that the eye might be sensitive to long-term overexposure to growth hormone (GH) and insulin-like growth factor-1 (IGF-1). We suggest that disease activity be taken into consideration on ophthalmological examination.

Patient-reported outcomes in patients with acromegaly treated with pegvisomant in the ACROSTUDY extension: A real-world experience

PURPOSE

To report the effects of pegvisomant (PEGV) treatment on patient-reported outcomes in acromegaly patients.

METHODS

We conducted an extension study of an open-label, multinational, non-interventional study (ACROSTUDY) evaluating the long-term safety and efficacy of PEGV for acromegaly in routine clinical practice. Enrolled patients were rollover patients from ACROSTUDY, or treatment naïve/semi-naïve (NSN; no PEGV within 6 months of enrollment). Exploratory efficacy endpoints were changes in symptoms with the Patient-Assessed Acromegaly Symptom Questionnaire (PASQ) and quality of life with the Acromegaly Quality of Life questionnaire (AcroQoL) analyzed by controlled or uncontrolled IGF-I levels. Results were analyzed in all patients, in NSN patient subgroup, and by diabetes status.

RESULTS

A total of 544 patients with acromegaly were enrolled, including 434 rollover subjects from ACROSTUDY and 110 NSN patients. Mean PEGV treatment duration was 7.8 years (range, 0-19.6 years). Overall, the majority of PASQ scores improved over time, but there was no significant difference between IGF-I controlled or uncontrolled groups. In the NSN subgroup, most PASQ and AcroQoL scores remained similar to baseline up to 1 year, regardless of IGF-I control. Patients with diabetes reported better PASQ scores over time with PEGV treatment, regardless of IGF-I control. IGF-I normalization increased from 10% of patients at baseline to more than 78% at year 10, with a mean daily PEGV dose of 18.7 mg.

CONCLUSIONS

Overall, patients treated with PEGV had small improvements in PASQ. While IGF-I normalization increased with PEGV treatment, IGF-I control had no effects on PASQ and AcroQoL scores.

High-risk pituitary adenomas and strategies for predicting response to treatment

High-risk pituitary adenomas are aggressive. They show clinical and imaging features similar to those of carcinomas, including infiltration of the surrounding brain structures, but lack cerebrospinal or systemic metastases. In addition, they display distinct behavior, including tendency for fast growth and frequent recurrences, which are difficult to control. The term "high-risk" adenoma was first introduced in the 4th edition of the World Health Organization Classification of Endocrine Tumors in 2017. Five defined adenoma types belong to this category, including sparsely granulated somatotroph, lactotroph in men, Crooke cell, silent corticotroph, and plurihormonal PIT-1 positive adenomas. The morphological and immunohistochemical characteristics of high-risk adenomas are herein described in detail. In addition, the clinical features and the treatment options are presented. This review focuses on predictive markers assessed by immunohistochemistry, which help clinicians to design the appropriate treatment strategies for high-risk adenomas. Somatostatin receptor status predicts effectiveness of postsurgical treatment with somatostatin analogs, and MGMT expression predicts response to treatment with temozolomide. This comprehensive review presents the clinical and pathological features of high-risk pituitary adenomas, underlines the contribution of immunohistochemistry, and emphasizes the leading role of pathology in the design of optimal clinical management.

Overview of the 2022 WHO Classification of Neuroendocrine Neoplasms

In this review, we detail the changes and the relevant features that are applied to neuroendocrine neoplasms (NENs) in the 2022 WHO Classification of Endocrine and Neuroendocrine Tumors. Using a question-and-answer approach, we discuss the consolidation of the nomenclature that distinguishes neuronal paragangliomas from epithelial neoplasms, which are divided into well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). The criteria for these distinctions based on differentiation are outlined. NETs are generally (but not always) graded as G1, G2, and G3 based on proliferation, whereas NECs are by definition high grade; the importance of Ki67 as a tool for classification and grading is emphasized. The clinical relevance of proper classification is explained, and the importance of hormonal function is examined, including eutopic and ectopic hormone production. The tools available to pathologists for accurate classification include the conventional biomarkers of neuroendocrine lineage and differentiation, INSM1, synaptophysin, chromogranins, and somatostatin receptors (SSTRs), but also include transcription factors that can identify the site of origin of a metastatic lesion of unknown primary site, as well as hormones, enzymes, and keratins that play a role in functional and structural correlation. The recognition of highly proliferative, well-differentiated NETs has resulted in the need for biomarkers that can distinguish these G3 NETs from NECs, including stains to determine expression of SSTRs and those that can indicate the unique molecular pathogenetic alterations that underlie the distinction, for example, global loss of RB and aberrant p53 in pancreatic NECs compared with loss of ATRX, DAXX, and menin in pancreatic NETs. Other differential diagnoses are discussed with recommendations for biomarkers that can assist in correct classification, including the distinctions between epithelial and non-epithelial NENs that have allowed reclassification of epithelial NETs in the spine, in the duodenum, and in the middle ear; the first two may be composite tumors with neuronal and glial elements, and as this feature is integral to the duodenal lesion, it is now classified as composite gangliocytoma/neuroma and neuroendocrine tumor (CoGNET). The many other aspects of differential diagnosis are detailed with recommendations for biomarkers that can distinguish NENs from non-neuroendocrine lesions that can mimic their morphology. The concepts of mixed neuroendocrine and non-neuroendocrine (MiNEN) and amphicrine tumors are clarified with information about how to approach such lesions in routine practice. Theranostic biomarkers that assist patient management are reviewed. Given the significant proportion of NENs that are associated with germline mutations that predispose to this disease, we explain the role of the pathologist in identifying precursor lesions and applying molecular immunohistochemistry to guide genetic testing.

Characteristics of Gut Microbiota in Patients with GH-Secreting Pituitary Adenoma

Prior study has demonstrated that gut microbiota at the genus level is significantly altered in patients with growth hormone (GH)-secreting pituitary adenoma (GHPA). Yet, no studies exist describing the state of gut microbiota at species level in GHPA. We performed a study using 16S rRNA amplicon sequencing in a cohort of patients with GH-secreting pituitary adenoma (GHPA, n = 28) and healthy controls (n = 67). Among them, 9 patients and 10 healthy controls were randomly chosen and enrolled in metagenomics shotgun sequencing, generating 280,426,512 reads after aligning to NCBI GenBank DataBase to acquire taxa information at the species level. Weighted UniFrac analysis revealed that microbial diversity was notably decreased in patients with GHPA, consistent with a previous study. With 16S rRNA sequencing, after correction for false-discovery rate (FDR), rank-sum test at the genus level revealed that the relative abundance of Oscillibacter and Enterobacter was remarkably increased in patients and Blautia and Romboutsia genera predominated in the controls, augmented by additional LEfSe (linear discriminant analysis effect size) analysis. As for further comparison at the species level with metagenomics sequencing, rank-sum test together with LEfSe analysis confirmed the enrichment of Alistipes shahii and Odoribacter splanchnicus in the patient group. Notably, LEfSe analysis with metagenomics also demonstrated that Enterobacter sp. DC1 and Enterobacter sp. 940 PEND, derived from Enterobacter, were both significantly enriched in patients. Functional analysis showed that amino acid metabolism pathway was remarkably enriched in GHPA, while carbohydrate metabolism pathway was notably enriched in controls. Further, significant positive correlations were observed between Enterobacter and baseline insulin-like growth factor 1 (IGF-1), indicating that Enterobacter may be strongly associated with GH/IGF-1 axis in GHPA. Our data extend our insight into the GHPA microbiome, which may shed further light on GHPA pathogenesis and facilitate the exploration of novel therapeutic targets based on microbiota manipulation.

IMPORTANCE Dysbiosis of gut microbiota is associated not only with intestinal disorders but also with numerous extraintestinal diseases. Growth hormone-secreting pituitary adenoma (GHPA) is an insidious disease with persistent hypersecretion of GH and IGF-1, causing increased morbidity and mortality. Researches have reported that the GH/IGF-1 axis exerts its own influence on the intestinal microflora. Here, the results showed that compared with healthy controls, GHPA patients not only decreased the alpha diversity of the intestinal flora but also significantly changed their beta diversity. Further, metagenomics shotgun sequencing in the present study exhibited that Enterobacter sp. DC1 and Enterobacter sp. 940 PEND were enriched in patients. Also, we were pleasantly surprised to find that the Enterobacter genus was strongly positively correlated with baseline IGF-1 levels. Collectively, our work provides the first glimpse of the dysbiosis of the gut microbiota at species level, providing a better understanding of the pathophysiological process of GHPA.

Oral Manifestations and Maxillo-Facial Features in the Acromegalic Patient: A Literature Review

Background: Acromegaly is a chronic disease caused by an abnormal secretion of growth hormone (GH) by a pituitary adenoma, resulting in an increased circulating concentration of insulin-like growth factor 1 (IGF-1). The main characteristics are a slow progression of signs and symptoms, with multisystemic involvement, leading to acral overgrowth, progressive somatic changes, and a complex range of comorbidities. Most of these comorbidities can be controlled with treatment. The literature reveals that the most evident and early signs are those related to soft tissue thickening and skeletal growth, especially in the head and neck region. Methods: The authors reviewed the available literature on the clinical oro-dental features of acromegaly, selecting articles from PubMed and Google Scholar. The aim of this review was to summarize all the reported clinical oro-dental features of acromegalic patients. Results: The most common facial dimorphisms involved the maxillo-facial district, with hypertrophy of the paranasal sinuses, thickening of the frontal bones, and protruding glabella, which may be associated with joint pain and clicks. Regarding the oro-dental signs, the most frequent are dental diastema (40–43%), mandibular overgrowth (22–24%), mandibular prognathism (20–22%), and macroglossia (54–58%). These signs of acromegaly can be significantly reduced with adequate treatment, which is more effective when initiated early. Conclusions: Increased awareness of acromegaly among dentists and maxillo-facial surgeons, along with the early identification of oro-facial changes, could lead to an earlier diagnosis and treatment, thereby improving patients’ quality of life and prognosis.

The role of the dentist and orthodontist in recognizing oro-facial manifestations of acromegaly: a questionnaire-based study

PURPOSE

Oro-facial manifestations of acromegaly are among the earliest signs of the disease and are reported by a significant number of patients at diagnosis. Despite this high prevalence of acromegaly oral manifestation, dentists do not play a pivotal role in acromegaly identification and diagnosis. The aim of our study was to evaluate the ability of dentists and orthodontists in the early recognition of the oro-facial manifestations of acromegaly.

METHODS

A telematic questionnaire was administered to dentists and orthodontists. The questionnaire included photos with facial and oral-dental details and lateral teleradiography of acromegaly patients (ACRO).

RESULTS

The study included 426 participants: 220 dentists and 206 orthodontists. Upon reviewing the photos, dentists most often observed mandibular prognathism and lips projection, while orthodontists also reported the impairment of relative soft tissue. Orthodontists, who usually use photos to document patients' oral-facial characteristics, paid more attention to oral-facial impairment than dentists. During dental assessment, 90% of the participants usually evaluated tongue size and appearance, diastemas presence, and signs of sleep impairment (mainly orthodontists). Orthodontists were also more able to identify sella turcica enlargement at teleradiography. A total of 10.8% of the participants had ACRO as patients and 11.3% referred at least one patient for acromegaly suspicion.

CONCLUSION

The study highlighted dentists' strategic role in identifying ACRO. Increasing dentists' awareness about acromegaly clinical issues may improve early diagnosis, potentially resulting in an increased quality of life and decreased mortality among ACRO.

Association of different pathologic subtypes of growth hormone producing pituitary adenoma and remission in acromegaly patients: a retrospective cohort study

BACKGROUND

Regarding the inconclusive results of previous investigations, this study aimed to determine the association between pathology, as a possible predictor, with remission outcomes, to know the role of pathology in the personalized decision making in acromegaly patients.

METHODS

A retrospective cohort study was performed on the consecutive surgeries for growth hormone (GH) producing pituitary adenomas from February 2015 to January 2021. Seventy-one patients were assessed for granulation patterns and prolactin co-expression as dual staining adenomas. The role of pathology and some other predictors on surgical remission was evaluated using logistic regression models.

RESULTS

Among 71 included patients, 34 (47.9%) patients had densely granulated (DG), 14 (19.7%) had sparsely granulated (SG), 23 (32.4%) had dual staining pituitary adenomas. The remission rate was about 62.5% in the patients with SG and DG adenomas named single staining and 52.2% in dual staining groups. Postoperative remission was 1.53-folds higher in the single staining adenomas than dual staining-one (non-significant). The remission rate was doubled in DG group compared to two other groups (non-significant). By adjusting different predictors, cavernous sinus invasion and one-day postoperative GH levels decreased remission rate by 91% (95% CI: 0.01-0.67; p = 0.015) and 64% (95% CI: 0.19-0.69; p < 0.001), respectively. Responses to the medications were not significantly different among three groups.

CONCLUSION

Various pathological subtypes of pituitary adenomas do not appear to have a predictive role in estimating remission outcomes. Cavernous sinus invasion followed by one-day postoperative GH is the strongest parameter to predict biochemical remission.

Densely granulated adenoma pattern is associated with an increased risk of obstructive sleep apnea in patients with acromegaly

OBJECTIVES

To explore the prevalence of obstructive sleep apnea (OSA) and the association between the adenoma granulation patterns and OSA in patients with acromegaly.

METHODS

An overnight polysomnography (PSG) assessment was carried out on participants with acromegaly. Results classified participants into a non-OSA group, mild to moderate OSA group, and severe OSA group. Morphological and biochemical analyses were performed. Demographic, clinical, biochemical, and polysomnographic data were compared among the three groups. Using logistic regression models, the risk of OSA in acromegalic subjects was estimated.

RESULTS

OSA was reported in 36 of 49 patients (74%) with acromegaly. Contrasted with the non-OSA group, OSA patients had a larger proportion of the densely granulated (DG) pattern. The OSA groups with DG acromegaly had a smaller maximum tumor diameter and Vol/2 than those with the sparsely granulated (SG) pattern. Furthermore, a higher growth hormone (GH) level (45.0 ± 36.9 vs 18.6 ± 15.8, P = 0.047) and GH index (28.4 ± 13.8 vs 6.6 ± 8.2, P = 0.003) were found in DG acromegaly patients with severe OSA. Additionally, there was a trend toward higher standardized insulin-like growth factor 1 (IGF-1) in patients with DG acromegaly than in those with SG acromegaly in the severe OSA group. After adjusting for potential confounding variables, the DG pattern was correlated with the risk of OSA (OR = 14.84, 95%CI 1.36-162.20, P = 0.027) in patients with acromegaly.

CONCLUSIONS

The findings indicate that a high prevalence of OSA exists in patients with acromegaly, and the DG pattern may be a risk factor for OSA in acromegaly.

Neuropathology of Pituitary Adenomas and Sellar Lesions

The pituitary gland is the site of numerous neoplastic and inflammatory processes. The overwhelmingly most frequent tumors arise from cells of the anterior lobe, the pituitary neuroendocrine tumors (PitNETs). Immunohistochemistry assay staining for pituitary hormones is the core tool for classifying PitNETs, resulting in the diagnosis of somatotroph PitNETs, lactotroph PitNETs, and so on. For cases showing no hormonal expression, the updated WHO classification system now considers the assessment of several transcription factors: PIT-1 (pituitary-specific POU-class homeodomain transcription factor); T-PIT (T-box family member TBX19); and SF-1 (steroidogenic factor regulating gonadotroph cell differentiation) before rendering a diagnosis of null cell adenoma. Other tumors and disease processes of this site often mimic PitNETs radiographically and sometimes even clinically (ie, compression of the optic chiasm). These potpourri of processes include germ cell neoplasms (especially germinomas), tumors that originate from Rathke's pouch (craniopharyngiomas, Rathke's cleft cyst), tumors that originate from the posterior lobe of the pituitary (pituicytoma, spindle cell oncocytoma, granular cell tumor), and tumors that originate from the meninges (especially meningiomas). In addition to neoplasms, several described inflammatory and related conditions exist that need to be distinguished from PitNETs. These include lymphocytic hypophysitis and Langerhans cell histiocytosis, a neoplastic disorder of histiocytes. In this review, we aim to briefly describe the main pituitary and sellar lesions, with emphasis on the most common tumors, the PitNETs.

Dual Characters of GH-IGF1 Signaling Pathways in Radiotherapy and Post-radiotherapy Repair of Cancers

Radiotherapy remains one of the most important cancer treatment modalities. In the course of radiotherapy for tumor treatment, the incidental irradiation of adjacent tissues could not be completely avoided. DNA damage is one of the main factors of cell death caused by ionizing radiation, including single-strand (SSBs) and double-strand breaks (DSBs). The growth hormone-Insulin-like growth factor 1 (GH-IGF1) axis plays numerous roles in various systems by promoting cell proliferation and inhibiting apoptosis, supporting its effects in inducing the development of multiple cancers. Meanwhile, the GH-IGF1 signaling involved in DNA damage response (DDR) and DNA damage repair determines the radio-resistance of cancer cells subjected to radiotherapy and repair of adjacent tissues damaged by radiotherapy. In the present review, we firstly summarized the studies on GH-IGF1 signaling in the development of cancers. Then we discussed the adverse effect of GH-IGF1 signaling in radiotherapy to cancer cells and the favorable impact of GH-IGF1 signaling on radiation damage repair to adjacent tissues after irradiation. This review further summarized recent advances on research into the molecular mechanism of GH-IGF1 signaling pathway in these effects, expecting to specify the dual characters of GH-IGF1 signaling pathways in radiotherapy and post-radiotherapy repair of cancers, subsequently providing theoretical basis of their roles in increasing radiation sensitivity during cancer radiotherapy and repairing damage after radiotherapy.

T2-weighted magnetic resonance imaging as a novel predictor of surgical remission in newly diagnosed pituitary macroadenomas presenting as acromegaly

BACKGROUND

Any preoperative diagnostic assessment that can predict the success of the operation in acromegaly will provide a positive impact on overall remission rates. The aim of this study is to reveal whether the signal intensity in T2-weighted Magnetic Resonance Imaging can predict postoperative results in acromegaly patients with macroadenoma.

METHODS

We analyzed our surgical results in regard to T2-weighted images in newly diagnosed consecutive 124 patients with acromegaly, operated between 2014 and 2019. The T2-intensity of the pure somatotroph macroadenomas was correlated with the clinical, radiological, surgical and histopathological characteristics of the acromegaly patients.

RESULTS

We found a predominance of T2-hyperintensity in our series (45%) and the T2-hypointense pure somatotroph adenomas were detected in only 34% of our patients. Total resection was performed in 72% of newly diagnosed acromegaly patients in this series. Accordingly, total resection was achieved in 69% of the T2-hyperintense group, 77% of the T2-hypointense group and 69% of the T2-isointense group. The surgical remission rates for the T2-hyper-, hypo- and isointense groups were 54.5%, 80.7%, and 68.7%, respectively. The surgical remission rate in the T2-hyperintense group was significantly lower than those of hypo- and isointense groups in newly diagnosed acromegaly patients.

CONCLUSIONS

This study demonstrates a close relationship between the T2 signal intensity and the surgical remission rates in acromegaly patients with macroadenoma. Preoperative T2-intensity images may predict the probability of post-surgical remission in patients with newly diagnosed acromegaly. Further support fort this idea comes from recent guidelines for acromegaly management in which the potential utility of using T2 intensity to optimize patient management has been emphasized.

An Update on Pituitary Neuroendocrine Tumors Leading to Acromegaly and Gigantism

An excess of growth hormone (GH) results in accelerated growth and in childhood, the clinical manifestation is gigantism. When GH excess has its onset after epiphyseal fusion at puberty, the overgrowth of soft tissue and bone results in acromegaly. Persistent GH excess in gigantism also causes acromegalic features that become evident in the adult years. The causes of GH excess are primarily lesions in the pituitary, which is the main source of GH. In this review, we provide an update on the clinical, radiological and pathologic features of the various types of pituitary neuroendocrine tumors (PitNETs) that produce GH. These tumors are all derived from PIT1-lineage cells. Those composed of somatotrophs may be densely granulated, resembling normal somatotrophs, or sparsely granulated with unusual fibrous bodies. Those composed of mammosomatotrophs also produce prolactin; rare plurihormonal tumors composed of cells that resemble mammosomatotrophs also produce TSH. Some PitNETs are composed of immature PIT1-lineage cells that do not resemble differentiated somatotrophs, mammosomatotrophs, lactotroph or thyrotrophs; these tumors may cause GH excess. An unusual oncocytic PIT1-lineage tumor known as the acidophil stem cell tumor is predominantly a lactotroph tumor but may express GH. Immature PIT1-lineage cells that express variable amounts of hormones alone or in combination can sometimes cause GH excess. Unusual tumors that do not follow normal lineage differentiation may also secrete GH. Exceptional examples of acromegaly/gigantism are caused by sellar tumors composed of hypothalamic GHRH-producing neurons, alone or associated with a sparsely granulated somatotroph tumor. Each of these various tumors has distinct clinical, biochemical and radiological features. Data from careful studies based on morphologic subtyping indicate that morphologic classification has both prognostic and predictive value.

Acromegaly accompanied by diabetes mellitus and polycystic kidney disease

Acromegaly is characterized by autonomous excessive growth hormone (GH) secretion, generally due to GH-producing pituitary adenoma, and is associated with various systemic comorbidities including diabetes mellitus. Polycystic kidney disease (PKD) is characterized by the growth of numerous cysts in the kidneys that deteriorate renal function. While possible renal effects of excessive GH exposure have been a current issue in experimental medicine, only five cases of coexisting acromegaly and PKD have been reported previously, and little is known regarding the influence of acromegaly on renal disease. We treated a 50-year-old male with diabetes mellitus who showed a sudden and rapid decline of renal function along with increasing proteinuria, which led to diagnoses of PKD and acromegaly. His urinary protein levels were increased together with excessive GH secretion and worsening glycemic control. An increase of total kidney volume was also noted. Transsphenoidal surgery for the pituitary adenoma was successfully performed. Marked improvement of hyperglycemia and proteinuria were observed after the surgery, but renal function was unchanged. The patient's clinical course suggested common aspects of excessive GH secretion as an accelerating factor of the progression of diabetic nephropathy and PKD via direct and indirect pathways. Although coexisting acromegaly and PKD is clinically rare, vigilance for early diagnosis of acromegaly is appropriate in patients with diabetes and/or PKD, especially in those showing unexpected exacerbation of renal dysfunction.

Proposal of a clinically relevant working classification of pituitary neuroendocrine tumors based on pituitary transcription factors

The immunohistochemistry (IHC) characterization of pituitary transcription factors (PTFs) PIT1, TPIT, and SF1, which enable the identification of three different adenohypophyseal cell lines, has been incorporated into the latest classification system of the World Health Organization (WHO) for pituitary adenomas. This change overturns the concept of the adenoma as solely a hormone producer and classifies these tumors based on their cell lineage. The aim of the study was to provide a diagnostic algorithm, based on IHC expression of hypophyseal hormones with potential use in diagnostic practice, contributing to an improved classification of pituitary adenomas. Our sample included 146 pituitary adenomas previously classified based on hormonal subtypes by IHC (former 2004 WHO criteria) and re-evaluated after the IHC quantification of PIT1, TPIT, and SF1 expression, under WHO 2017 recommendations. We assessed the correlation between expression of PTFs and the classification as per hormonal IHC and correlated clinicopathological profiles based on PTFs. The IHC study of PTFs allowed reclassification of 82% of tumors that were negative for all pituitary hormones, with 21 positive cases for SF1 (reclassified as gonadotroph tumors), 1 positive case for TPIT (reclassified as a corticotroph tumor), and 4 positive cases for PIT1. Using SF1 enabled detection of a substantial portion of gonadotroph tumors, reducing the estimated prevalence of null cell tumors to less than 5%, and identification of plurihormonal pituitary neuroendocrine tumors with PIT1-SF1 coexpression and hormone-negative PIT1s, a group in which we did not observe differences in the clinical behavior compared with the rest of the tumors of the same cell lineage.Our results suggest that applying a diagnostic algorithm based on the study of PTFs could contribute to improving the classification of pituitary adenomas. By adding TPIT assessment, we propose a two-step algorithm, with hypophyseal hormones being used in a selective modality, depending on initial results.

Pituitary Macroadenoma Presenting as Acromegaly and Subacute Pituitary Apoplexy: Case Report and Literature Review

We report a case of a patient who presented to our endocrinology department for gradual onset with headache, fatigue, and weight loss over the course of one month. On physical examination, the patient showcased coarse facial features, acral enlargement, and other features suggestive of acromegaly. However, despite a clinical picture consistent with this diagnosis, serum growth hormone and insulin-like growth factor 1 were below reference range. Furthermore, secondary adrenal insufficiency, secondary hypothyroidism, and hypogonadotropic hypogonadism were discovered. Imaging revealed a pituitary macroadenoma and after a neurosurgical consult, the patient underwent transsphenoidal hypophysectomy and the suspected diagnosis of subacute pituitary adenoma apoplexy (SPAA) was confirmed via histology of resected tissue. Additionally, we review the literature for other case reports of patients with acromegaly or acromegalic features who underwent pituitary apoplexy to identify patient characteristics, presumed etiologies, and presence of biochemical cure of acromegaly following SPAA.