Overview of the 2017 WHO Classification of Pituitary Tumors

Single-cell and spatial transcriptome analyses reveal tumor heterogeneity and immune remodeling involved in pituitary neuroendocrine tumor progression

Pituitary neuroendocrine tumors (PitNETs) can be invasive or aggressive, yet the mechanisms behind these behaviors remain poorly understood, impeding treatment advancements. Here, we integrat single-cell RNA sequencing and spatial transcriptomics, analyzing over 177,000 cells and 35,000 spots across 57 tissue samples. This comprehensive approach facilitates the identification of PitNETs tumor populations and characterizes the reconfiguration of the tumor microenvironment (TME) as PitNETs progress and invade. We trace the trajectory of TPIT-lineage PitNETs and identify an aggressive tumor cluster marked by elevated p53-mediated proliferation and a higher Trouillas classification, both associated with tumor progression. Additionally, we document the heterogeneity of immune stromal cells within PitNETs, particularly noting the enrichment of SPP1+ tumor associated macrophages (TAMs) in invasive tumors. These TAMs facilitate tumor invasion through the SPP1-ITGAV/ITGB1 signaling pathway. Our in-depth single-cell and spatial analysis of PitNETs uncovers the molecular dynamics within the TME, suggesting potential targets for therapeutic intervention.

Non-recurrent mutations and copy number changes predominate pituitary adenoma genomes

OBJECTIVE

Pituitary adenomas (PAs) are common neoplasms. Our current understanding of the molecular basis of PA formation is incomplete. Routine implementation of targeted genomics has enabled the discovery of rare, potentially clinically actionable events.

METHODS

We used a cancer-focused gene panel to sequence a cohort of 171 PAs from patients who underwent surgery at Brigham and Women's Hospital from 2012 to 2020.

RESULTS

We identified known genetic variants enriched in specific PA subtypes: GNAS (somatotroph) and USP8 (Cushing's disease). Total mutational burden did not vary across adenoma subtypes; most adenomas possessed a few non-recurrent mutations in various established oncogenes and tumor suppressors. In contrast, the burden of copy number alterations varied widely across adenoma subtypes and was associated with higher MIB1 labeling index. We identified frequent deletions spanning MEN1 in prolactinomas and silent corticotroph adenomas, and subtype-specific copy number changes including 16p, 16q alterations in somatotroph adenomas without GNAS mutations. Within the corticotroph lineage, adenomas leading to Cushing's disease had few copy number alterations while silent corticotroph adenomas had numerous.

CONCLUSIONS

This study highlights a role for individualized genetic events in PA formation and suggests that divergent patterns of genomic instability may facilitate tumorigenesis even within the same lineage. Taken together, we demonstrate how gene panels may illuminate novel biology in endocrine tumors.

Comprehensive Classification of Surgically Resected Pituitary Neuroendocrine Tumors: Updates From a Single-Institution Experience Based on the WHO 5th Edition

BACKGROUND

The 5th edition of WHO classification (WHO5) renamed pituitary adenoma as pituitary neuroendocrine tumor (PitNET), aligning with NET nomenclature from other sites. This study investigated the clinicopathological characteristics of surgically resected PitNET based on the WHO5 classification.

METHODS

A retrospective analysis was conducted on 210 cases of surgically resected and pathologically confirmed PitNET treated at Seoul National University Hospital from 2021 to 2023. The tumors were graded using the French five-tiered grading system proposed by Trouillas et al. Detailed information on grade 3 metastatic PitNET cases is provided.

RESULTS

The cohort's median age was 53 years (age range: 8-84 years), with a male-to-female ratio of 1:1.1. Mean tumor size was 2.5 cm (range: 0.1-6.5 cm). Macroadenomas predominated (91.9%), followed by microadenoma (6.7%), and giant tumors (1.4%), with 56.2% extending suprasellarly. SF1-lineage PitNET was most prevalent (49.5%), followed by PIT1-lineage (23.3%) and TPIT-lineage (17.1%). Null cell tumors (5.7%) and unclassified plurihormonal PitNET (4.3%) were rare. PIT1-lineage PitNET comprised somatotrophs (47.0%), mature plurihormonal PIT1 lineage tumors (18.4%), thyrotrophs (16.3%), immature PIT1-lineage tumors (16.3%), and acidophilic stem cell tumors (n=1), however, there was no lactotroph PitNET. Among SF1-lineage tumors, serologically non-functional tumors predominated (79%), while, immunohistochemically, 71.2% were gonadotrophin (FSH/LH)-positive. Tumor grades by the French five-tiered classification system were distributed as follows: grade 1a (58.1%), 1b (17.6%), 2a (16.2%), 2b (7.1%), and 3 (1.0%). Two cases of metastatic corticotroph PitNET were observed: The first case, a 50-year-old female had liver metastasis and experienced tumor recurrence 7 years after his initial diagnosis of PitNET, ultimately dying 9.5 years later. The primary tumor appeared bland, but the metastatic tumor exhibited a high mitotic rate and a Ki-67 index was 48%. The second case involved a 44-year-old man with metastases to the paranasal sinus, liver, and bone. Despite showing initial bland histopathology and a low proliferation index, this tumor displayed aggressive behavior. The patient had a recurrence 1.5 years after diagnosis, with additional metastases emerging 3 years later. He survived for 8.0 years and is currently disease-free following surgery, chemotherapy, and radiotherapy.

CONCLUSION

This comprehensive analysis of surgically resected PitNETs using the new WHO5 classification provides valuable insights into the distribution of the subtypes in the surgical cohort. Key findings were the predominant gonadotroph PitNET, the absence of lactotroph PitNET, and the rarity of null cell tumors in surgical cases. The lack of lactotrophs was mainly due to medical treatment. This study highlights the discrepancy between serological and immunohistochemical findings of SF1-lineage PitNETs. While metastatic PitNET cases showed poor prognosis, the predictive value of the French grading system for PitNET requires further validation through extended follow-up.

A Brief Overview of Molecular Biology in Pituitary Adenomas with a Focus on Aggressive Lesions

Arising from the anterior lobe of the hypophysis, pituitary neuroendocrine tumors (PitNETs), previously known as pituitary adenomas, constitute an intricate and heterogeneous entity. Although they are defined as benign pathology, these tumors can often invade neighboring structures and demonstrate aggressive behavior. The continuous advancement of molecular biology has begun to shed light on the genetic mutations behind the development and evolution of this pathology, providing a better understanding. Notwithstanding, the rising occurrence in recent decades can mainly be attributed to advanced diagnostic techniques; however, these tumors continue to increase in prevalence and incidence, creating a heavy burden on healthcare systems. Consequently, the need for further studies is dire, primarily due to a lack of tailored therapeutic approaches. Thus, this article aims to offer a brief overview of the molecular biology behind these complex tumors to contribute, even on a small scale, to more comprehensive care.

Indocyanine green fluorescence in endoscopic transsphenoidal resection of pituitary neuroendocrine tumors: a systematic review

BACKGROUND

Over the last decade, endoscope integrated indocyanine green (E-ICG) fluorescence has been introduced in endoscopic skull base surgery. E-ICG seems to be a promising tool for intraoperative tissue differentiation, distinguishing pituitary neuroendocrine tumors (PitNET) from pituitary gland. More recent technical advancements have made E-ICG with simultaneous near-infrared/white-light overlay imaging available. E-ICG may improve intraoperative tumor identification, enabling more precise surgery and ultimately improved patient outcome. This systematic review evaluates the use of E-ICG for PitNET surgery.

METHODS

A systematic review was performed in accordance with PRISMA guidelines. PubMed, EMBASE, MedLine and Scopus databases were searched using different terms for "pituitary adenoma" combined with "Indocyanine green". Data from relevant original papers were extracted and analyzed.

RESULTS

Fifteen studies were included in the final analysis. The studies employed different ICG administration and fluorescence assessment protocols. Endpoints and methodology were heterogenous. Study populations varied from one to 39 cases. A total of 193 patients underwent transsphenoidal endoscopic surgery with E-ICG for PitNET. ICG dosage varied from 5 mg to 25 mg/kg. Thirteen studies administered ICG intraoperatively. Eleven studies utilized first-generation endoscopes, requiring toggling between near infrared light fluorescence and white light. Second generation dual or overlay mode endoscopes were used in four studies. Tumor fluorescence was assessed in eleven studies (141 cases). Six studies utilized a quantitative method to assess ICG-fluorescence. Seven studies specifically reported surgical complications. No safety issues regarding ICG use were reported.

CONCLUSIONS

The current literature is mainly based on small single center cohorts and case-studies, presenting a wide variety of approaches. Procedures and intraoperative assessment of fluorescence were mainly performed utilizing first-generation ICG endoscopes. There is lack of consensus in terms of ICG as an intraoperative tumor marker. Endoscopic ICG seems a promising tool for intraoperative real-time tissue differentiation, including vascular structures, tumor and pituitary gland.

Oncocytic pituicytoma in a patient with Cushing's disease: a case report and narrative literature review

Background

Posterior pituitary tumors (PPTs) are extremely rare, with fewer than 400 cases reported to date. In 2022, the World Health Organization (WHO) classified four types of tumors originating from the posterior pituitary: traditional pituicytoma, oncocytic pituicytoma, granular pituicytoma, and ependymal pituicytoma. To our knowledge, only one subject with coexistence of Cushing's disease and oncocytic pituicytoma (spindle cell oncocytoma) has been reported, but the clinical features of this patient were not described in detail.

Case presentation

We presented a case of a patient with Cushing's syndrome and a pituitary mass. Transsphenoidal surgery was performed, and pathologic examination revealed two distinct tumors: a corticotroph adenoma with a diameter of less than 2 mm and a larger oncocytic pituicytoma. Post-surgery serum cortisol was 51 nmol/L, indicating complete remission. Corticotroph adenoma or corticotroph hyperplasia was identified after surgery in less than half of the subjects with Cushing's disease and PPT.

Conclusions

Our study indicates that Cushing's disease in patients with PPT may be caused by the existence of collision lesions, with corticotroph adenoma or hyperplasia being difficult to detect due to their small dimensions.

Preoperative Assessment of Ki-67 Labeling Index in Pituitary Adenomas Using Delta-Radiomics Based on Dynamic Contrast-Enhanced MRI

BACKGROUND

Ki-67 labeling index (Ki-67 LI) is a proliferation marker that is correlated with aggressive behavior and prognosis of pituitary adenomas (PAs). Dynamic contrast-enhanced MRI (DCE-MRI) may potentially contribute to the preoperative assessment of Ki-67 LI.

PURPOSE

To investigate the feasibility of assessing Ki-67 LI of PAs preoperatively using delta-radiomics based on DCE-MRI.

STUDY TYPE

Retrospective.

POPULATION

605 PA patients (female = 47.1%, average age = 52.2) from two centers (high Ki-67 LI (≥ 3%) = 229; low Ki-67 LI (< 3%) = 376), divided into a training set (n = 313), an internal validation set (n = 196), and an external validation set (n = 96).

FIELD STRENGTH/SEQUENCE

1.5-T and 3-T, DCE-MRI.

ASSESSMENT

This study developed a non-delta-radiomics model based on the non-delta-radiomic features directly extracted from four phases, a delta-radiomics model based on the delta-radiomic features, and a combined model integrating clinical parameters (Knosp grade and tumor diameter) with delta-radiomic features. U test, recursive feature elimination (RFE), and least absolute shrinkage and selection operator (LASSO) regression were utilized to select important radiomic features. Support vector machine (SVM), XGBoost (XGB), logistic regression (LR), and Gaussian naive Bayes (GNB) were utilized to develop the models.

STATISTICAL TESTS

Receiver operating characteristic (ROC) curve. Calibration curve. Decision curve analysis (DCA). Intraclass correlation coefficients (ICC). DeLong test for ROC curves. U test or t test for numerical variables. Fisher's test or Chi-squared test for categorical variables. A p-value < 0.05 was considered statistically significant.

RESULTS

The combined model demonstrated the best performance in preoperatively assessing the Ki-67 LI of PAs, achieving AUCs of 0.937 and 0.897 in the internal and external validation sets, respectively. The models based on delta-radiomic features outperformed the non-delta-radiomic model.

DATA CONCLUSION

A delta-radiomics-based model using DCE-MRI may show high diagnostic performance for preoperatively assessing the Ki-67 LI status of PAs.

EVIDENCE LEVEL

3 Technical Efficacy: Stage 2.

Anlotinib may have a therapeutic effect on papillary craniopharyngiomas without the BRAFv600e mutation

BACKGROUND

Although successful treatment of papillary craniopharyngiomas (PCPs) with BRAFv600e inhibitors has been reported in clinical trials, studies have shown that approximately 10% of PCPs lack the BRAFv600e mutation and that BRAFv600e inhibitors may not be significantly effective against these tumors. However, no studies have focused specifically on BRAFv600e- PCPs.

METHODS

Spatial transcriptome sequencing was performed on calcified PCP tissue to identify novel subtypes of PCP cells. The findings were validated via pathological methods in 51 PCP samples. Primary PCP cells from BRAFv600e- PCP patients and BRAFv600e+ PCP patients were isolated and then injected into the brains of nude mice via stereotactic surgery to establish a stable mouse model of human-originated PCP. Model mice were treated with vemurafenib, a BRAF inhibitor, and anlotinib, an angiogenesis inhibitor. BRAFv600e-PCP patients were treated with anlotinib in a phase 1 clinical trial. Changes in the tumors of the model mice and patients were monitored via pathological methods, CT and MRI.

RESULTS

Most of calcified PCPs were negative for the BRAFv600e mutation, and findings from the mouse model confirmed that vemurafenib may not have a significant therapeutic effect on BRAFv600e- PCPs. However, the mouse model verified that, anlotinib may have a significant therapeutic effect on BRAFv600e- PCPs. Two patients with BRAFv600e- PCPs participated in a phase 1 clinical trial and received anlotinib therapy; their tumors disappeared after 3 months of therapy and did not recur within 24 months follow-up after stopping the treatment.

CONCLUSION

BRAFv600e- PCPs are characterized by calcification and do not respond to the BRAF inhibitor vemurafenib, and for which the angiogenesis inhibitor anlotinib may have a significant therapeutic effect.

Machine Learning Prediction of Pituitary Macroadenoma Consistency: Utilizing Demographic Data and Brain MRI Parameters

Consistency of pituitary macroadenomas is a key determinant in surgical outcomes, with non-soft consistency linked to more complications and incomplete resections. This study aimed to develop a machine learning model to predict the consistency of pituitary macroadenomas to improve surgical planning and outcomes. A retrospective study of patients with pituitary macroadenomas was conducted. Data included brain magnetic resonance imaging findings (diameter and apparent diffusion coefficient), patient demographics (age and sex), and tumor consistency. Seventy patients were evaluated, 59 with soft consistency and 11 with non-soft consistency. The support vector machine (SVM) was the best model with ROC AUC score of 83.3% [95% CI 65.8, 97.6], AP AUC of 69.8% [95% CI 41.3, 91.1], sensitivity of 73.1% [95% CI 44.4, 100], specificity of 89.8% [95% CI 82, 96.7], F1 score of 0.63 [95% CI 0.36, 0.83], and Matthews correlation coefficient score of 0.57 [95% CI 0.29, 0.79]. These findings indicate a significant improvement over random classification, as confirmed by a permutation test (p < 0.05). Additionally, the model had a 67.4% probability of outperforming the second-best model in cross-validation, as determined through Bayesian analysis, and demonstrated statistical significance (p < 0.05) compared to non-ensemble models. Using explainability heuristics, both 2D and 3D probability maps highlighted areas with a higher probability of non-soft consistency. The attributes most influential in the correct classification by our best model were male sex and age ≤ 42.25 years. Despite some limitations, the SVM model showed promise in predicting tumor consistency, which could aid in surgical planning. To address concerns about generalizability, we have created an open-access repository to promote future external validation studies and collaboration with other research centers, with the goal of enhancing model prediction through transfer learning.

Phosphatidylinositol promoted the proliferation and invasion of pituitary adenoma cells by regulating POU1F1 expression

Invasiveness of pituitary adenoma is the main cause of its poor prognosis, mechanism of which remains largely unknown. In this study, the differential proteins between invasive and non-invasive pituitary tumors (IPA and NIPA) were identified by TMT labeled quantitative proteomics. The differential metabolites in venous bloods from patients with IPA and NIPA were analyzed by untargeted metabolomics. Proteomic data showed that the top five up-regulated proteins were AD021, C2orf15, PLCXD3, HIST3H2BB and POU1F1, and the top five down-regulated proteins were AIPL1, CALB2, GLUD2, SLC4A10 and GTF2I. Metabolomic data showed that phosphatidylinositol (PI) was most remarkably up-regulated and melibiose was most obviously down-regulated. Further investigation demonstrated that PI stimulation increased the expression of PITPNM1, POU1F1, C2orf15 and LDHA as well as the phosphorylation of AKT and ERK, and promoted the proliferation, migration and invasion of GH3 cells, which were blocked by PITPNM1knockdown. Inhibiting AKT phosphorylation reduced the expression of POU1F1, C2orf15 and LDHA in PI-stimulated cells while activating AKT increased their expression in PITPNM1-silencing cells, which was similar to the function of ERK. POU1F1 silence suppressed the expression of LDHA and C2orf15. Luciferase report assay and ChIP assay demonstrated that POU1F1 positively regulated the transcription of LDHA and C2orf15. In addition, PI propelled the metastasis of GH3 cells in vivo, and elevated the expression of PITPNM1, POU1F1, C2orf15 and LDHA. These results suggested that elevated serum PI might contribute to the proliferation and invasion of pituitary adenoma by regulating the expression of PITPNM1/AKT/ERK/POU1F1 axis.

DNA Methylation in Pituitary Adenomas: A Scoping Review

Pituitary adenomas are a diverse group of neoplasms with variable clinical behavior. Despite advances in genetic analysis, understanding the role of epigenetic modifications, particularly DNA methylation, remains an area under investigation. This scoping review aimed to update and synthesize the current body of literature on DNA methylation in pituitary adenomas, focusing on methodological advancements and clinical correlations. A systematic search conducted across multiple databases, including Embase, Scopus, MEDLINE, and CENTRAL, identified 107 eligible studies. Early methods, such as methylation-restricted digestion and methylation-specific PCR (MSP), have evolved into more comprehensive approaches, such as chip-based DNA methylation analysis. Key findings suggest that genes like POMC, SOCS-1, and RASSF1A show a significant association between methylation and clinical behavior. However, methylation patterns alone are insufficient to fully explain tumorigenesis. Emerging data suggest that DNA methylation might serve as a prognostic marker for invasive growth and recurrence, but further longitudinal studies are needed. This review highlights the need for future research to explore the methylome more thoroughly and to better define the clinical impact of epigenetic modifications in pituitary adenomas.

Distinct clinical characteristics and prognosis of pediatric-onset growth hormone-secreting pituitary adenoma (GHPA) patients compared to adult-onset patients

PURPOSE

To explore the clinical characteristics, treatment, and prognosis of growth hormone-secreting pituitary adenoma (GHPA) patients with pediatric-onset, so as to facilitate clinical management.

METHODS

A retrospective cohort study was carried out between 102 pediatric-onset GHPA patients admitted to our hospital from January 2013 to June 2022 and 204 adult-onset GHPA patients who were randomly matched.

RESULTS

GHPA with pediatric-onset was predominantly male, associated with higher proportion of genetic syndromes, longer course, and delayed diagnosis. Clinical symptoms of visual field defects and menstrual abnormality were more common. The pediatric-onset group exhibited higher growth hormone (GH) nadir during oral glucose tolerance test (OGTT), higher rates of hyperprolactinemia, larger maximum diameter of adenoma, and higher rates of optic chiasm compression, suprasellar invasion, and pituitary apoplexy. Hypertension, diabetes, and obstructive sleep apnea-hypopnea syndrome (OSAHS) were more common in the adult-onset group. Echocardiography results were similar between the two groups. The pediatric-onset group owned significantly higher treatment scores and proportions of multimodal therapy modality, more surgical complications, and a higher proportion of ki67 ≥ 3%. There was no significant difference in the final cure rate, but male patients with adult-onset had a worse prognosis. The recurrence rate was also similar between two groups. Hypopituitarism was more prevalent in the pediatric-onset group, while the adult-onset group had a higher incidence of other tumors.

CONCLUSION

Pediatric-onset GHPA patients exhibit distinct clinical characteristics compared to adult-onset patients. Multimodal therapy modalities could help to achieve a cure rate comparable to that of adult-onset patients.

PD-L1 expression in PitNETs: Correlations with the 2022 WHO classification

Introduction

and research question: Prognostic factors to predict the behavior of pituitary neuroendocrine tumors (PitNET) are scarce. PD-L1 expression was associated with prognosis in other neuroendocrine neoplasms and we analyzed PD-L1 expression in PitNET, according to the 2022 WHO classification.

Material and methods

A retrospective analysis was performed. Immunohistochemistry was used to define PD-L1 expression, which was quantified as TPS (tumor proportion score). The primary outcome was to assess the correlation between PD-L1 expression and transcription factors (TF), namely T-pit, Pit-1, SF-1 and GATA-3. As secondary outcomes, we evaluated the association between PD-L1 expression and proliferation indexes.

Results

Eighty-eight patients were included. The largest group belonged to the SF-1-lineage (48%), followed by tumors of the Pit-1 lineage (32%) and T-pit lineage (17%). PD-L1 expression was associated with Pit-1 expression (p < 0.001) and with the somatotroph, lactotroph and mammosomatotroph subgroups. A TPS ⩾35% showed a 100% sensitivity for the mammosomatotroph subtype, while the optimal cut-off point was 20% for somatotroph and 15% for lactotroph tumors. PD-L1 expression was negatively associated with SF-1 and GATA3 expression(p < 0.001), with an optimal cut-point ≤5%. No association was found between PD-L1 expression and immunohistochemical proliferative factors but PD-L1 expression was associated with female sex and a younger age at diagnosis.

Conclusion

PD-L1 expression was associated with PIT-1 lineage, while it was downregulated in SF-1-lineage tumors. No correlation was found with proliferative factors. The role of PD-L1 expression in determining the biological behavior of PitNET remains debated and larger studies are necessary to further confirm these findings.

Growth Hormone-Secreting Pituitary Adenoma: Dura Mater Invasion Is Not a Predictor of Acromegaly Persistence After Trans-Sphenoidal Surgery

Objectives: In pituitary adenomas, examinations of surgical specimens have shown that dural invasion occurs in 42-85% of cases. No studies about dura mater invasion have been conducted specifically in acromegaly patients. The aim of the present study was to evaluate the relationship between histologically dural invasion and the main features of GH-secreting adenomas. Methods: This retrospective study included all consecutive acromegaly patients who underwent neurosurgery at our university hospital between 2017 and 2020. The following data were collected: (1) clinical, biochemical and morphological data at diagnosis, at three months, one year after neurosurgery, and at last follow-up; (2) pathological features (dura mater invasion, immunohistochemical analyses, proliferation index Ki-67, p53, and granulation pattern); and (3) radiological features on magnetic resonance images. Results: Of 35 acromegaly patients, 11 had dural invasion (INV+ 31%) and 24 did not (INV- 69%). GH levels at diagnosis were greater in INV+ patients (p = 0.02), and a GH value > 27 ng/mL was able to distinguish INV+ patients (Sensitivity 80%, Specificity 73%, AUC 0.760, p = 0.006). Indeed, patients with GH > 27 ng/mL at diagnosis had a tenfold greater risk of dura mater invasion (OR 10.7; 95% CI 1.74-65.27, p = 0.005). No differences were found in the other clinical, biochemical, morphological, radiological and pathological features. Regarding remission likelihood, IGF-1 levels at diagnosis were lower in cured patients (p = 0.03). Conclusions: The GH level at diagnosis is the only parameter significantly associated with dura mater invasion. Lower IGF-1 levels at diagnosis are significantly associated with remission one year after surgery.

High-Grade Progression, Sarcomatous Transformation, and/or Metastasis of Pituitary Neuroendocrine Neoplasms (PitNENs): The UCSF Experience

Pituitary neuroendocrine tumors (PitNET) that metastasize comprise ~ 0.2% of adenohypophyseal tumors are aggressive and are challenging to treat. However, many non-metastatic tumors are also aggressive. Herein, we review 21 specimens from 13 patients at UCSF with metastatic PitNETs (CSF or systemic, N = 7 patients), high-grade pituitary neuroendocrine neoplasms (HG-PitNEN, N = 4 patients), and/or PitNETs with sarcomatous transformation (PitNET-ST, N = 5 patients). We subtyped cases using the World Health Organization (WHO) and International Agency for Research on Cancer (IARC) criteria for neuroendocrine neoplasms (NENs). Lineage subtypes included acidophil stem cell, null cell, thyrotroph, corticotroph, lactotroph, and gonadotroph tumors. The median Ki-67 labeling index was 25% (range 5-70%). Lack of p16 was seen in 3 cases, with overexpression in 2. Strong diffuse p53 immunopositivity was present in 3 specimens from 2 patients. Loss of Rb expression was seen in 2 cases, with ATRX loss in one. Molecular analysis in 4 tumors variably revealed TERT alterations, homozygous CDKN2A deletion, aneuploidy, and mutations in PTEN, TP53, PDGFRB, and/or PIK3CA. Eight patients (62%) died of disease, 4 were alive at the last follow-up, and 1 was lost to the follow-up. All primary tumors had worrisome features, including aggressive lineage subtype, high mitotic count, and/or high Ki-67 indices. Additional evidence of high-grade progression included immunohistochemical loss of neuroendocrine, transcription factor, and/or hormone markers. We conclude that metastatic PitNET is not the only high-grade form of pituitary NEN. If further confirmed, these histopathologic and/or molecular features could provide advanced warning of biological aggressiveness and be applied towards a future grading scheme.

The prospective roles of exosomes in pituitary tumors

Pituitary neuroendocrine tumors are common, typically benign intracranial neoplasms arising from well-differentiated anterior pituitary cells with prevalence of clinically relevant pituitary tumor of 89 in 100 000 people. Despite the growing number of published studies, there is still a need for diagnostic and predictive biomarkers of pituitary adenomas. Prompt determination of tendency of the tumor for invasive growth and aggressive behavior would allow for earlier and more effective treatment. Extracellular vesicles (EVs), including exosomes, are particles released by cells containing cell-specific cargo including a variety of bioactive molecules, such as DNA, messenger RNA, microRNA, long non-coding RNA, circular RNA, proteins, and lipids surrounded by lipid membranes, which act as mediators of cell to cell communication. The ability of exosomes to reflect the functional state of the tumor, transport informative molecules, and accessibility in body fluids make them promising candidates in the search for biomarkers and new therapeutic methods. This study aims to investigate the involvement of exosomes in the pathology of pituitary adenoma and their potential clinical applications.

Clinical features of pituitary carcinoma: analysis based on a case report and literature review

Introduction

Pituitary carcinoma (PC) is an extremely rare tumor of the adenohypophysis, which manifests as craniospinal dissemination and/or systemic metastasis. The diagnosis of PC is particularly difficult, as the clinical diagnosis only can be made after the metastasis is found. Owing to the complex diagnostic process and less effective treatments, the clinical prognosis of PC is usually very poor. Hence, it is of great significance to illustrate the diagnosis and treatment course of PC.

Methods

In this case report, we described a 48-year-old male patient who was diagnosed with pituitary adenoma (PA) initially and then was diagnosed with PC eventually after spinal cord metastasis was found, and we illustrated the treatment course as well. Furthermore, we summarized all the published case reports until now and provided a comprehensive review of the diagnosis, treatment, prediction, and clinical outcome of PC.

Results and Conclusions

We found that most PC patients had adrenocorticotropic hormone/prolactin (ACTH/PRL)-secreting tumors, Ki-67 ≥ 10%, and P53 positivity, which may have the potential to predict the transformation from PA to PC; surgery excision combined with temozolomide (TMZ) and radiotherapy is helpful to prolong the survival of PC patients.

LCM-RNAseq Highlights Intratumor Heterogeneity and a lncRNA Signature from Archival Tissues of GH-Secreting PitNETs

BACKGROUND

This study explores the potential for hidden variations within seemingly uniform regions of growth hormone-secreting pituitary neuroendocrine tumors (GH-PitNETs). We employed archived tissue samples using Laser Capture Microdissection Sequencing (LCM-RNAseq) to probe the molecular landscape of these tumors at a deeper level.

METHODS

A customized protocol was developed to extract, process, and sequence small amounts of RNA from formalin-fixed, paraffin-embedded (FFPE) tissues derived from five patients with GH-secreting PitNETs and long-term follow-up (≥10 years). This approach ensured precise isolation of starting material of enough quality for subsequent sequencing.

RESULTS

The LCM-RNAseq analysis revealed a surprising level of diversity within seemingly homogeneous tumor regions. Interestingly, the 30 most highly expressed genes included the well-known long noncoding RNA (lncRNA) MALAT1. We further validated the levels of MALAT1 and of other tumor-associated lncRNAs using digital droplet PCR.

CONCLUSIONS

This study demonstrates the potential of LCM-RNAseq to unlock hidden molecular diversity within archived pituitary tumor samples. By focusing on specific cell populations, we identified lncRNAs expressed at different levels within the tumors, potentially offering new insights into the complex biology of GH-secreting PitNETs. This evidence prompts further research into the role of lncRNAs in pituitary neuroendocrine tumor aggressiveness and personalized treatment strategies.

LONG-TERM NATURAL HISTORY OF GIANT NULL CELL PITUITARY ADENOMA

Pituitary adenomas that extend to the ventricular system are extremely rare. We present a 5-year natural history of a giant null cell pituitary adenoma with invasion into the cavernous sinus extending to the third ventricle. MRI series that were available could be useful for neurosurgeons, ophthalmologists, and endocrinologists as well as radiologists. Patients with the diagnosis of pituitary adenoma that are certain according to the radiological and clinical examination should be consulted by a neurosurgeon experienced in endoscopic endonasal surgery, a neuroendocrinologist, and an ophthalmologist. The surgery postponement in such cases results in disability and quality of life worsening. At that time, the surgery of giant pituitary adenomas demands high skills, and the risk of postoperative complications is high. The proper treatment modality including earlier surgery seems to be favorable for patient outcome.

Spontaneous Cerebrospinal Fluid Rhinorrhea in Pre-operative Pituitary Adenoma: A Report of Two Cases

Pituitary macroadenomas are neuroendocrine tumors residing in the base of the skull. First-line therapies for prolactin-secreting adenomas (prolactinoma) include medical treatment with dopamine agonists and neurosurgical intervention. Cerebrospinal fluid (CSF) rhinorrhea is a well-known complication following skull base tumor treatment; however, spontaneous CSF rhinorrhea as the initial presenting feature of such tumors is rare. We present two cases of spontaneous CSF rhinorrhea in pre-operative invasive pituitary macroadenomas. Invasive pituitary macroadenomas have the potential to disrupt local skull base structures such as the sellar floor and cavernous sinus. Early warning signs can help aid in prompt diagnosis and successful treatment. Spontaneous CSF rhinorrhea as the initial presenting symptom is rare and may be pivotal in the early diagnosis of pituitary adenomas.

Clinicopathological analysis of non-functioning pituitary adenomas (PAs) according to the 2022 WHO classification

PURPOSE

For asymptomatic non-functioning pituitary adenomas (NFPAs), conservative approaches such as observation are preferred. However, some NFPAs exhibit poor prognoses. Thus, the purpose of this study was to investigate clinicopathological characteristics of tumors for identifying those with unfavorable prognoses.

METHODS

A total of 125 patients with NFPAs who underwent surgery between November 2017 and December 2022 at our institution were retrospectively analyzed. Clinical, radiological, and pathological data, including hormone profiles, tumor size, presence of cavernous sinus invasion, and Ki-67 index levels, were reviewed. High-risk PAs were identified according to 2022 WHO criteria. Statistical analyses including Kaplan-Meier survival analysis and Cox regression were performed to evaluate factors associated with tumor progression or recurrence.

RESULTS

A high-risk group demonstrated a significantly higher rate of tumor progression/recurrence than a low-risk group (p-value = 0.004). In multivariate analysis, the high-risk group at the time of diagnosis remained as an independent prognostic factor for NFPAs (p-value = 0.0148). The high-risk group also had a higher percentage of younger patients (80.0% in the high-risk group vs. 62.2% in the low-risk group, p-value = 0.016) and female patients (91.4% vs. 34.4%, p< 0.001). The presence of cavernous sinus invasion and higher Ki-67 index levels were more commonly observed in the high-risk group, although these factors did not significantly impact the overall prognosis.

CONCLUSION

Our findings indicate that patients with high-risk NFPAs have a more aggressive disease course and a higher rate of progression or recurrence. This high-risk group has higher prevalence of younger and female patients. They may benefit from closer monitoring and possibly more aggressive treatment approaches.

Expression assays of selected lncRNAs in non-functioning pituitary adenomas

PURPOSE

Non-functioning pituitary adenomas (NFPAs) are a group of these neoplasms originated from the adenohypophyse and do not show evidence of hormonal oversecretion. However, different genes and lncRNAs have been found to be dysregulated in these samples.

MATERIAL AND METHODS

In this study, in order to identify novel biomarkers, a set of regulatory lncRNAs for the two important hub genes, i.e. STAT3 and EGFR were selected and subjected to experimental investigation. These lncRNAs were EGFR-AS1 for the EGFR gene, and LINC00240, FALEC and SNHG12 for the STAT3 gene.

RESULTS

All studied genes were down-regulated in NFPA samples compared with normal tissues adjacent to the tumors (NTATs), except for FALEC whose expression was not different between these two sets of samples. EGFR was the most significantly down-regulated gene in NFPAs (Expression ratio (95% CI) = 0.009 (0.002-0.04), P value < 0.0001). ROC curve analyses proposed that the expression levels of SNHG12, EGFR, EGFR-AS1 and LINC00240 can be used to distinguish NFPAs from NTATs with AUC values of 0.88, 0.83, 0.7 and 0.66, respectively. Spearman's correlation analyses showed significant correlations between FALEC and EGFR-AS1 in both types of tissues, and between FALEC and EGFR in NFPAs. Moreover, expression of LINC00240 was correlated with EGFR-AS1, FALEC and SNHG12 in NFPAs.

CONCLUSION

Taken together, EGFR and STAT3-related lncRNAs may be involved in the pathogenesis of NFPA.

Multi-Dynamic-Multi-Echo-based MRI for the Pre-Surgical Determination of Sellar Tumor Consistency: a Quantitative Approach for Predicting Lesion Resectability

PURPOSE

Pre-surgical information about tumor consistency could facilitate neurosurgical planning. This study used multi-dynamic-multi-echo (MDME)-based relaxometry for the quantitative determination of pituitary tumor consistency, with the aim of predicting lesion resectability.

METHODS

Seventy-two patients with suspected pituitary adenomas, who underwent preoperative 3 T MRI between January 2020 and January 2022, were included in this prospective study. Lesion-specific T1-/T2-relaxation times (T1R/T2R) and proton density (PD) metrics were determined. During surgery, data about tumor resectability were collected. A Receiver Operating Characteristic (ROC) curve analysis was performed to investigate the diagnostic performance (sensitivity/specificity) for discriminating between easy- and hard-to-remove by aspiration (eRAsp and hRAsp) lesions. A Mann-Whitney-U-test was done for group comparison.

RESULTS

A total of 65 participants (mean age, 54 years ± 15, 33 women) were enrolled in the quantitative analysis. Twenty-four lesions were classified as hRAsp, while 41 lesions were assessed as eRAsp. There were significant differences in T1R (hRAsp: 1221.0 ms ± 211.9; eRAsp: 1500.2 ms ± 496.4; p = 0.003) and T2R (hRAsp: 88.8 ms ± 14.5; eRAsp: 137.2 ms ± 166.6; p = 0.03) between both groups. The ROC analysis revealed an area under the curve of 0.72 (95% CI: 0.60-0.85) at p = 0.003 for T1R (cutoff value: 1248 ms; sensitivity/specificity: 78%/58%) and 0.66 (95% CI: 0.53-0.79) at p = 0.03 for T2R (cutoff value: 110 ms; sensitivity/specificity: 39%/96%).

CONCLUSION

MDME-based relaxometry enables a non-invasive, pre-surgical characterization of lesion consistency and, therefore, provides a modality with which to predict tumor resectability.

Granulation Patterns of Functional Corticotroph Tumors Correlate with Tumor Size, Proliferative Activity, T2 Intensity-to-White Matter Ratio, and Postsurgical Early Biochemical Remission

Unlike somatotroph tumors, the data on correlates of tumor granulation patterns in functional TPIT lineage pituitary neuroendocrine tumors (corticotroph tumors) have been less uniformly documented in most clinical series. This study evaluated characteristics of 41 well-characterized functional corticotroph tumors consisting of 28 densely granulated corticotroph tumors (DGCTs) and 13 sparsely granulated corticotroph tumors (SGCTs) with respect to preoperative clinical and radiological findings, tumor proliferative activity (including mitotic count and Ki-67 labeling index), and postoperative early biochemical remission rates. The median (interquartile range (IQR)) tumor size was significantly larger in the SGCT group [16.00 (16.00) mm in SGCT vs 8.5 (9.75) mm in DGCT, p = 0.049]. T2-weighted signal intensity and T2 intensity (quantitative) did not yield statistical significance based on tumor granulation; however, the T2 intensity-to-white matter ratio was significantly higher in SGCTs (p = 0.049). The median (IQR) Ki-67 labeling index was 2.00% (IQR 1.00%) in the DGCT group and 4.00% (IQR 7.00%) in the SGCT group (p = 0.043). The mitotic count per 2 mm2 was higher in the SGCT group (p = 0.001). In the multivariate analysis, the sparse granulation pattern (SGCT) remained an independent predictor of a lower probability of early biochemical remission irrespective of the tumor size and proliferative activity (p = 0.012). The current study further supports the impact of tumor granulation pattern as a biologic variable and warrants the detailed histological subtyping of functional corticotroph tumors as indicated in the WHO classification of pituitary neuroendocrine tumors. More importantly, the assessment of the quantitative T2 intensity-to-white matter ratio may serve as a preoperative radiological harbinger of SGCTs.

Clinical implications of the 2022 WHO classification on the multidisciplinary management of PitNETS patients

The review explores the 2022 update to the World Health Organization (WHO) classification of pituitary adenomas, now referred to as pituitary neuroendocrine tumors (PitNETs), and his possible impact on the clinical management of PitNET patients. The review highlights the differences and the evolution from the 2017 to 2022 version, with the current classification considering the lineage of the tumor cells, cell type, hormones produced, and other auxiliary characteristics for a comprehensive histological classification. The revision in terminology reflects a broader perspective on neuroendocrine neoplasia. The new approach based on transcription factors, hormone expression and other biomarkers has allowed a major revision of the nomenclature and a more accurate classification of pituitary adenomas. Furthermore, in some cases this approach is also assuming a prognostic value, useful in clinical practice. However, despite this elaborate classification and stratification, the review points out the lack of a robust grading or staging system and suggests the need for further research and validation of diagnostic methods. Despite these limitations, the revised classification presents a significant step towards understanding and managing PitNETs patients.

Diagnosis and Management of Aggressive/Refractory Growth Hormone-Secreting Pituitary Neuroendocrine Tumors

The majority of acromegaly and gigantism are caused by growth hormone-secreting pituitary neuroendocrine tumors (PitNETs). Most cases can be cured or controlled by surgery, medical therapy, and/or radiotherapy. However, a few of these tumors are resistant to traditional therapy and always have a poor prognosis. The title aggressive/refractory is used to differentiate them from pituitary carcinomas. To date, there is no definitive conclusion on how to diagnose aggressive/refractory growth hormone-secreting PitNETs, which may have slowed the process of exploring new therapeutical strategies. We summarized the literature described diagnosis and treatment of the disease. Potential disease markers and prospective therapies were also included.

Prolactin Secreting Pituitary Carcinoma and the Role of Peptide Receptor Radionuclide Therapy: A Brief Report

Pituitary carcinoma is a rare entity comprising 0.1-0.2% of all pituitary tumors and presents significant diagnostic and therapeutic challenges. Intraspinal drop metastasis in these tumors is even rarer. We report a case of a prolactin secreting pituitary carcinoma with intracranial metastasis and multiple intraspinal drop metastasis. This is the first case where 68Gallium labelled [1,4,7,10 - tetraazacyclododecane - 1,4,7,10 - tetraacetic acid] -1- NaI3 - octreotide (68Ga-DOTANOC) whole-body positron emission tomography-computed tomography (PET-CT) has been used in a case of malignant prolactinoma, in an attempt to ascertain the somatostatin receptor (SSTR) expression on tumor cells. Through this paper, we suggest that SSTR targeted radionuclide therapy could have a potential role in aggressive pituitary tumors and pituitary carcinomas similar to the promising role of lutetium-labelled peptides in inoperable or metastasized gastroentero-pancreatic neuroendocrine tumors (GEP-NETs).

Efficacy and safety of radiosurgery in acromegaly

Stereotactic radiosurgery (SRS) more and more frequently plays a crucial role in the treatment of acromegaly. We provide a systematic review of the literature and meta-analysis, according to PRISMA, on SRS for the management of growth hormone (GH)-secreting pituitary adenomas, including several radiosurgical techniques, with the aim of describing efficacy and safety of this treatment. A weighted random effects model was used to calculate pooled outcome estimates. From 346 abstract reviews, 27 retrospective studies were included. Despite the variability in hormonal remission criteria and the heterogeneity between treatment guidelines among included studies, most of them reported an endocrine remission rate between 40% and 60%. Random effects meta-analysis for overall endocrine remission and 5-year probability of remission estimate after SRS were 46% (95% CI: 39-53%) and of 48% (95% CI: 38-57%), respectively. Random effects meta-analysis for new hypopituitarism estimate after SRS was 23% (95% CI: 17-29%). Furthermore, incidence of radiation induced optic neuropathy after SRS ranged between 0% and 6% This meta-analysis confirms and quantifies safety and effectiveness of SRS to achieve endocrine remission after surgical management in acromegaly.

Genome-Wide DNA Methylation Profiling as a Prognostic Marker in Pituitary Adenomas-A Pilot Study

BACKGROUND

The prediction of the regrowth potential of pituitary adenomas after surgery is challenging. The genome-wide DNA methylation profiling of pituitary adenomas may separate adenomas into distinct methylation classes corresponding to histology-based subtypes. Specific genes and differentially methylated probes involving regrowth have been proposed, but no study has linked this epigenetic variance with regrowth potential and the clinical heterogeneity of nonfunctioning pituitary adenomas. This study aimed to investigate whether DNA methylation profiling can be useful as a clinical prognostic marker.

METHODS

A DNA methylation analysis by Illumina's MethylationEPIC array was performed on 54 pituitary macroadenomas from patients who underwent transsphenoidal surgery during 2007-2017. Twelve patients were excluded due to an incomplete postoperative follow-up, degenerated biobank-stored tissue, or low DNA methylation quality. For the quantitative measurement of the tumor regrowth rate, we conducted a 3D volumetric analysis of tumor remnant volume via annual magnetic resonance imaging. A linear mixed effects model was used to examine whether different DNA methylation clusters had different regrowth patterns.

RESULTS

The DNA methylation profiling of 42 tissue samples showed robust DNA methylation clusters, comparable with previous findings. The subgroup of 33 nonfunctioning pituitary adenomas of an SF1-lineage showed five subclusters with an approximately unbiased score of 86%. There were no overall statistically significant differences when comparing hazard ratios for regrowth of 100%, 50%, or 0%. Despite this, plots of correlated survival estimates suggested higher regrowth rates for some clusters. The mixed effects model of accumulated regrowth similarly showed tendencies toward an association between specific DNA methylation clusters and regrowth potential.

CONCLUSION

The DNA methylation profiling of nonfunctioning pituitary adenomas may potentially identify adenomas with increased growth and recurrence potential. Larger validation studies are needed to confirm the findings from this explorative pilot study.

Integrative clinical, hormonal, and molecular data associate with invasiveness in acromegaly: REMAH study

INTRODUCTION

Growth hormone (GH)-secreting pituitary tumors (GHomas) are the most common acromegaly cause. At diagnosis, most of them are macroadenomas, and up to 56% display cavernous sinus invasion. Biomarker assessment associated with tumor growth and invasion is important to optimize their management.

OBJECTIVES

The study aims to identify clinical/hormonal/molecular biomarkers associated with tumor size and invasiveness in GHomas and to analyze the influence of pre-treatment with somatostatin analogs (SSAs) or dopamine agonists (DAs) in key molecular biomarker expression.

METHODS

Clinical/analytical/radiological variables were evaluated in 192 patients from the REMAH study (ambispective multicenter post-surgery study of the Spanish Society of Endocrinology and Nutrition). The expression of somatostatin/ghrelin/dopamine system components and key pituitary/proliferation markers was evaluated in GHomas after the first surgery. Univariate/multivariate regression studies were performed to identify association between variables.

RESULTS

Eighty percent of patients harbor macroadenomas (63.8% with extrasellar growth). Associations between larger and more invasive GHomas with younger age, visual abnormalities, higher IGF1 levels, extrasellar/suprasellar growth, and/or cavernous sinus invasion were found. Higher GH1 and lower PRL/POMC/CGA/AVPR1B/DRD2T/DRD2L expression levels (P < .05) were associated with tumor invasiveness. Least Absolute Shrinkage and Selection Operator's penalized regression identified combinations of clinical and molecular features with areas under the curve between 0.67 and 0.82. Pre-operative therapy with DA or SSAs did not alter the expression of any of the markers analyzed except for DRD1/AVPR1B (up-regulated with DA) and FSHB/CRHR1 (down-regulated with SSAs).

CONCLUSIONS

A specific combination of clinical/analytical/molecular variables was found to be associated with tumor invasiveness and growth capacity in GHomas. Pre-treatment with first-line drugs for acromegaly did not significantly modify the expression of the most relevant biomarkers in our association model. These findings provide valuable insights for risk stratification and personalized management of GHomas.

Comparative analysis of intraoperative and imaging features of invasive growth in pituitary adenomas

BACKGROUND

Most pituitary adenomas (PAs), also termed pituitary neuroendocrine tumors, are benign in nature and can be treated effectively by surgical resection, medical treatment, and in special cases by radiotherapy. However, invasive growth can be an important feature of a more aggressive behavior and adverse prognosis. The extension of PAs into the cavernous sinus can be categorized according to the Knosp criteria on magnetic resonance imaging (MRI). Comparative analyses of MRI features and intraoperative findings of invasive growth regarding different clinical factors are still scarce.

MATERIALS AND METHODS

We performed a retrospective single-center analysis of 764 PAs that were surgically treated between October 2004 and April 2018. Invasive growth was assessed according to the surgical reports and preoperative MRI (Knosp criteria). Clinical data, such as patient age at diagnosis and gender, histopathological adenoma type, and extent of resection, were collected.

RESULTS

Invasive features on MRI were seen in 24.4% (Knosp grades 3A-4, 186/764) of the cases. Intraoperatively, invasion was present in 42.4% (324/764). Complete resection was achieved in 80.0% of adenomas and subtotal resection, in 20.1%. By multivariate analysis, invasion according to intraoperative findings was associated with the sparsely granulated corticotroph (SGCA, P = .0026) and sparsely granulated somatotroph (SGSA, P = .0103) adenoma type as well as age (P = .0287). Radiographic invasion according to Knosp grades 3A-4 correlated with age (P = .0098), SGCAs (P = .0005), SGSAs (P = .0351), and gonadotroph adenomas (P = .0478). Both criteria of invasion correlated with subtotal resection (P = .0001, respectively).

CONCLUSIONS

Both intraoperative and radiographic signs of invasive growth are high-risk lesions for incomplete extent of resection and occur more frequently in older patients. A particularly high prevalence of invasion can be found in the SGCA and SGSA types. Cavernous sinus invasion is also more common in gonadotroph adenomas. Usage of the Knosp classification is a valuable preoperative estimation tool.

Pituitary tumours without distinct lineage differentiation express stem cell marker SOX2

CONTEXT

The recent WHO 2022 Classification of pituitary tumours identified a novel group of 'plurihormonal tumours without distinct lineage differentiation (WDLD)'. By definition, these express multiple combinations of lineage commitment transcription factors, in a monomorphous population of cells.

OBJECTIVES

To determine the expression of stem cell markers (SOX2, Nestin, CD133) within tumours WDLD, immature PIT-1 lineage and acidophil stem cell tumours, compared with committed cell lineage tumours.

METHODS

Retrospective evaluation of surgically resected pituitary tumours from St Vincent's Hospital, Sydney. Patients were selected to cover a range of tumour types, based on transcription factor and hormone immunohistochemistry. Clinical data was collected from patient files. Radiology reports were reviewed for size and invasion. Samples were analysed by immunohistochemistry and RT-qPCR for SF-1, PIT-1, T-PIT, SOX2, Nestin and CD133. Stem cell markers were compared between tumours WDLD and those with classically "mature" types.

RESULTS

On immunohistochemistry, SOX2 was positive in a higher proportion of tumours WDLD compared with those meeting WHO lineage criteria, 7/10 v 10/42 (70 v 23.4%, p = 0.005). CD133 was positive in 2/10 tumours WDLD but 0/41 meeting lineage criteria, P = 0.003. On RT-qPCR, there was no significant difference in relative expression of stem cell markers (SOX2, CD133, Nestin) between tumours with and WDLD.

CONCLUSIONS

Our study is the first to biologically characterise pituitary tumours WDLD. We demonstrate that these tumours exhibit a higher expression of the stem cell marker SOX2 compared with other lineage-differentiated tumours, suggesting possible involvement of stem cells in their development.

Genome-wide loss of heterozygosity predicts aggressive, treatment-refractory behavior in pituitary neuroendocrine tumors

Pituitary neuroendocrine tumors (PitNETs) exhibiting aggressive, treatment-refractory behavior are the rare subset that progress after surgery, conventional medical therapies, and an initial course of radiation and are characterized by unrelenting growth and/or metastatic dissemination. Two groups of patients with PitNETs were sequenced: a prospective group of patients (n = 66) who consented to sequencing prior to surgery and a retrospective group (n = 26) comprised of aggressive/higher risk PitNETs. A higher mutational burden and fraction of loss of heterozygosity (LOH) was found in the aggressive, treatment-refractory PitNETs compared to the benign tumors (p = 1.3 × 10-10 and p = 8.5 × 10-9, respectively). Within the corticotroph lineage, a characteristic pattern of recurrent chromosomal LOH in 12 specific chromosomes was associated with treatment-refractoriness (occurring in 11 of 14 treatment-refractory versus 1 of 14 benign corticotroph PitNETs, p = 1.7 × 10-4). Across the cohort, a higher fraction of LOH was identified in tumors with TP53 mutations (p = 3.3 × 10-8). A machine learning approach identified loss of heterozygosity as the most predictive variable for aggressive, treatment-refractory behavior, outperforming the most common gene-level alteration, TP53, with an accuracy of 0.88 (95% CI: 0.70-0.96). Aggressive, treatment-refractory PitNETs are characterized by significant aneuploidy due to widespread chromosomal LOH, most prominently in the corticotroph tumors. This LOH predicts treatment-refractoriness with high accuracy and represents a novel biomarker for this poorly defined PitNET category.

Clinicopathological Analysis of Densely and Sparsely Granulated Somatotroph Tumors of Pituitary

OBJECTIVE

Somatotroph tumors are the second most common type of pituitary neuroendocrine tumors, which can be further classified into 2 subtypes-densely granulated somatotroph tumors (DGSTs) and sparsely granulated somatotroph tumors (SGSTs). The aim of this study was to investigate the clinical significance of the 2 subtypes in a retrospective analysis.

METHODS

From the database of the Ningbo Clinical Pathology Diagnosis Center, we collected patients diagnosed with pituitary somatotroph tumors. We then compiled pertinent clinical and radiological data and proceeded with histopathological examination involving hematoxylin-eosin staining and immunohistochemical staining. Subsequent analysis compared the 2 subtypes using either χ2 test or Fisher exact test.

RESULTS

We analyzed 40 cases of somatotroph tumors, 18 cases DGSTs and 22 SGSTs. Male-to-female ratio was 5:4 for DGSTs and 4:7 for SGSTs. Mean age was 52.83 years for DGSTs and 47.18 years for SGSTs. Statistically significant differences were observed between the DGST and SGST groups in invasiveness (P = 0.0267) and postoperative remission (P = 0.007). Cells of both DGSTs and SGSTs exhibited coexpression of PIT1, growth hormone, and CAM5.2, although the patterns of CAM5.2 expression differed between the 2 subtypes.

CONCLUSIONS

The efficacy of CAM5.2 staining in distinguishing between DGSTs and SGSTs was demonstrated. SGSTs, with their increased invasiveness and lower remission rate, are a high-risk subtype. The histological subtype of somatotroph tumors plays a crucial role in guiding treatment decisions and prognostic evaluation in affected patients.

The biological behavior and clinical outcome of pituitary adenoma are affected by the microenvironment

BACKGROUND

Pituitary adenoma is one of the most common brain tumors. Most pituitary adenomas are benign and can be cured by surgery and/or medication. However, some pituitary adenomas show aggressive growth with a fast growth rate and are resistant to conventional treatments such as surgery, drug therapy, and radiation therapy. These tumors, referred to as refractory pituitary adenomas, often relapse or regrow in the early postoperative period. The tumor microenvironment (TME) has recently been identified as an important factor affecting the biological manifestations of tumors and acts as the main battlefield between the tumor and the host immune system.

MAIN BODY

In this review, we focus on describing TME in pituitary adenomas and refractory pituitary adenomas. Research on the immune microenvironment of pituitary adenomas is currently focused on immune cells such as macrophages and lymphocytes, and extensive research and experimental verifications are still required regarding other components of the TME. In particular, studies are needed to determine the role of the TME in the specific biological behaviors of refractory pituitary adenomas, such as high invasion, fast recurrence rate, and high tolerance to traditional treatments and to identify the mechanisms involved.

CONCLUSION

Overall, we summarize the similarities and differences between the TME of pituitary adenomas and refractory pituitary adenomas as well as the changes in the biological behavior of pituitary adenomas that may be caused by the microenvironment. These changes greatly affect the outcome of patients.

Association between Intracellular Calcium Signaling and Tumor Recurrence in Human Non-Functioning Pituitary Adenomas

Clinically non-functioning pituitary adenomas (CNFPAs) are the second most frequent sellar tumor among studies on community-dwelling adults. They are characterized by the absence of hormonal hypersecretion syndrome, and patients present with compressive symptoms, such as a headache and visual field defects. Immunohistochemically, most CNFPAs are of gonadotrope differentiation, with only a few of them being truly null cell adenomas. Although these tumors express receptors for one or more hypothalamic releasing hormones, to what extent this has an impact on the biological and clinical behavior of these neoplasms remains to be defined. In this research, we evaluated the basal and hypothalamic secretagogue-stimulated intracellular calcium mobilization in 13 CNFPAs, trying to correlate this response to the phenotypic features of the patients. Our results indicate that the recurrence of a CNFPA correlates positively with cellular responsiveness, as measured by spontaneous intracellular calcium activity and the ability to respond to multiple hypothalamic secretagogues. We conclude that this finding may be a useful tool for predicting the clinicopathologic behavior of CNFPAs, by testing the variation of cellular responsiveness to hypothalamic secretagogues.

Clinical application of reserved gastric tube in neuroendoscopic endonasal surgery for pituitary tumor

BACKGROUND

The neuroendoscopic approach has the advantages of a clear operative field, convenient tumor removal, and less damage, and is the development direction of modern neurosurgery. At present, transnasal surgery for sphenoidal pituitary tumor is widely used. But it has been found in clinical practice that some patients with this type of surgery may experience post-operative nausea and vomiting and other discomforts.

AIM

To explore the effect of reserved gastric tube application in the neuroendoscopic endonasal resection of pituitary tumors.

METHODS

A total of 60 patients who underwent pituitary adenoma resection via the endoscopic endonasal approach were selected and randomly divided into the experimental and control groups, with 30 in each group. Experimental group: After anesthesia, a gastric tube was placed through the mouth under direct vision using a visual laryngoscope, and the fluid accumulated in the oropharynx was suctioned intermittently with low negative pressure throughout the whole process after nasal disinfection, during the operation, and when the patient recovered from anesthesia. Control group: Given the routine intraoperative care, no gastric tube was left. The number of cases of nausea/vomiting/aspiration within 24 h post-operation was counted and compared between the two groups; the scores of pharyngalgia after waking up, 6 h post-operation, and 24 h post-operation. The frequency of postoperative cerebrospinal fluid leakage and intracranial infection were compared. The hospitalization days of the two groups were statistically compared.

RESULTS

The times of postoperative nausea and vomiting in the experimental group were lower than that in the control group, and the difference in the incidence of nausea was statistically significant (P < 0.05). After the patient woke up, the scores of sore throat 6 h after the operation and 24 h after operation were lower than those in the control group, and the difference was statistically significant (P < 0.05). The number of cases of postoperative cerebrospinal fluid leakage and intracranial infection was higher than that of the control group, but there was no statistically significant difference from the control group (P > 0.05). The hospitalization days of the experimental group was lower than that of the control group, and the difference was statistically significant (P < 0.05).

CONCLUSION

Reserving a gastric tube in the endoscopic endonasal resection of pituitary tumors, combined with intraoperative and postoperative gastrointestinal decompression, can effectively reduce the incidence of nausea, reduce the number of vomiting and aspiration in patients, and reduce the complications of sore throat The incidence rate shortened the hospitalization days of the patients.

Clinical and Molecular Characteristics of Gonadotroph Pituitary Tumors According to the WHO Classification

Since 2017, hormone-negative pituitary neuroendocrine tumors expressing the steroidogenic factor SF1 have been recognized as gonadotroph tumors (GnPT) but have been poorly studied. To further characterize their bio-clinical spectrum, 54 GnPT defined by immunostaining for FSH and/or LH (group 1, n = 41) or SF1 only (group 2, n = 13) were compared and studied for SF1, βFSH, βLH, CCNA2, CCNB1, CCND1, caspase 3, D2R, and AIP gene expression by qRT-PCR. Immunohistochemistry for AIP and/or D2R was performed in representative cases. Overall, patients were significantly younger in group 1 (P = 0.040 vs group 2), with a similar trend excluding recurrent cases (P = 0.078), and no significant difference in gender, tumor size, invasion or Ki67. SF1 expression was similar in both groups but negatively correlated with the patient's age (P = 0.013) and positively correlated with βLH (P < 0.001) expression. Beta-FSH and AIP were significantly higher in group 1 (P = 0.042 and P = 0.024, respectively). Ki67 was unrelated to gonadotroph markers but positively correlated with CCNB1 (P = 0.001) and negatively correlated with CCND1 (P = 0.008). D2R and AIP were strongly correlated with each other (P < 0.001), and both positively correlated with SF1, βFSH, βLH, and CCND1. AIP immunopositivity was frequently observed in both groups, with a similar median score, and unrelated to Ki67. D2R immunostaining was best detected with a polyclonal antibody and mostly cytoplasmic. This study indicates that hormone-negative GnPT tend to occur in older patients but do not significantly differ from other GnPT in terms of invasion or proliferation. It also points out the current limits of D2R immunostaining in such tumors.

Clinical study on the selection of endoscopes and microscopes for transsphenoidal surgery of non-aggressive pituitary macroadenoma and microadenoma and the influencing factors of hyposmia after endoscopic transsphenoidal surgery

Background and objective

Transsphenoidal surgery, including endoscopic and microscopic resection, is the first choice of treatment for pituitary tumors. With the widespread application of neuroendoscopy in recent decades, there has been a trend to replace microscopes. In clinical practice, we have found that in transsphenoidal surgery for non-invasive microadenomas and macroadenomas, microscopy can achieve a higher total resection rate, shorter operation time, lower incidence of postoperative complications, and faster recovery of olfaction. This study aimed to explore the selection of endoscopes and microscopes for non-aggressive transsphenoidal surgery for pituitary adenomas and the factors affecting olfactory recovery.

Methods

From August 2019 to October 2022, 93 patients with non-aggressive microadenomas and macroadenomas via the transsphenoidal approach were selected from the First Affiliated Hospital of Harbin Medical University and treated with rich experience in pituitary tumor subspecialty microscopy and endoscopic surgery. Different surgical methods were used to divide the patients into microscopic (n = 35) and endoscopic (n = 58) groups. The total tumor removal rate, intraoperative blood loss, operation time and cost, postoperative hospital stay, recovery of visual function, postoperative changes in hormone levels, complication rate, and recovery from complications 3 months after the operation were compared between the two groups.

Results

There were no significant differences in the tumor removal rate, postoperative visual acuity, and visual field recovery between the two groups (p > 0.05). There was a significant difference in the recovery rate of olfactory function between the two groups 3 months after the operation (p < 0.05), and there was no significant difference in the incidence of other complications (p > 0.05); Compared with the two groups, the microscope group had shorter operation time, longer postoperative hospital stay, less average operation cost and less blood loss, and the difference was statistically significant (p < 0.05). The position of the nasal septum mucosal flap incision was a risk factor for hyposmia 3 months after the operation.

Conclusion

Microsurgery and endoscopic surgery are suitable surgical treatments for nonaggressive microadenomas and macroadenomas. The total tumor removal and postoperative hormone remission rates of the two surgical methods were approximately the same. However, the microsurgery group had a shorter operation time, less intraoperative blood loss, faster olfactory function recovery, and a lower average operation cost. The position of the nasal septal mucosal flap incision was a risk factor for hyposmia at 3 months postoperatively. Hyposmia is less likely to occur when the superior edge of the nasal septal mucosal flap incision is not higher than the lower edge of the ipsilateral superior turbinate.

Is radiomics a useful addition to magnetic resonance imaging in the preoperative classification of PitNETs?

BACKGROUND

The WHO 2021 introduced the term pituitary neuroendocrine tumours (PitNETs) for pituitary adenomas and incorporated transcription factors for subtyping, prompting the need for fresh diagnostic methods. Current biomarkers struggle to distinguish between high- and low-risk non-functioning PitNETs. We explored if radiomics can enhance preoperative decision-making.

METHODS

Pre-treatment magnetic resonance (MR) images of patients who underwent surgery between 2015 and 2019 with available WHO 2021 classification were used. The tumours were manually segmented on the T1w, T1-contrast enhanced, and T2w images using 3D Slicer. One hundred Pyradiomic features were extracted from each MR sequence. Models were built to classify (1) somatotroph and gonadotroph PitNETs and (2) high- and low-risk subtypes of non-functioning PitNETs. Feature were selected independently from the MR sequences and multi-sequence (combining data from more than one MR sequence) using Boruta and Pearson correlation. Support vector machine (SVM), logistic regression (LR), random forest (RF), and multi-layer perceptron (MLP) were the classifiers used. Data imbalance was addressed using the Synthetic Minority Oversampling TEchnique (SMOTE). Performance of the models were evaluated using area under the receiver operating curve (AUC), accuracy, sensitivity, and specificity.

RESULTS

A total of 222 PitNET patients (train, n = 149; test, n = 73) were enrolled in this retrospective study. Multi-sequence-based LR model discriminated best between somatotroph and gonadotroph PitNETs, with a test AUC of 0.84, accuracy of 0.74, specificity of 0.81, and sensitivity of 0.70. Multi-sequence-based MLP model perfomed best for the high- and low-risk non-functioning PitNETs, achieving a test AUC of 0.76, accuracy of 0.67, specificity of 0.72, and sensitivity of 0.66.

CONCLUSIONS

Utilizing pre-treatment MRI and radiomics holds promise for distinguishing high-risk from low-risk non-functioning PitNETs based on the latest WHO classification. This could assist neurosurgeons in making critical decisions regarding surgery or alternative management strategies for PitNETs after further clinical validation.

Clinical Implications of Pituitary Adenomas Exhibiting Dual Transcription Factor Staining: A Case Series of 27 Patients

OBJECTIVE

According to the 2017 World Health Organization classification of neuro-endocrine tumors, pituitary adenomas (PAs) are classified according to immunoexpression of the pituitary-specific transcription factors (TFs). A small subset of PAs exhibit multiple TF staining on immunohistochemistry and we present a series of 27 pathologically-confirmed cases of dual TF staining PAs (dsTF-PAs), and report clinically relevant implications.

METHODS

A retrospective chart review of a multi-institutional database of patients with PAs surgically resected between 2008-2021 was performed. PAs expressing immunopositivity 2+ TFs. Patient demographics, neuro-imaging characteristics, histopathologic findings, and clinical data were collected.

RESULTS

Twenty-seven patients had pathologically verified dsTF-PAs, of whom 17 were female (63%), with ages ranging from 20-84 years. Twenty-three (85.2%) patients harbored functional PAs, with acromegaly being the most common functional subtype (86.4%). The most common combination of TFs within a single tumor was PIT-1/SF-1 (85.2%). Six PAs exhibited Knosp cavernous sinus invasion grades of 3 or 4 and the Ki-67 labeling index was ≥3% in 6 patients (24.0%) and all stained for PIT-1/SF-1. Hormonal remission was achieved in 78% of functional dsTF-PAs. No PAs showed evidence of recurrence or progression over the mean follow-up period of 28.5 months.

CONCLUSIONS

PAs exhibiting dsTF-PAs represent a small but clinically relevant diagnostic subset of PAs according to the 2021 World Health Organization criteria, as a majority are GH-producing. Precise classification using TF staining plays a key role in understanding the biology of these tumors. Favorable outcomes can be achieved in this subset of PAs with evolving TF classification.

Clinical and Pathological Features of Pit1/SF1 Multilineage Pituitary Neuroendocrine Tumor

BACKGROUND AND OBJECTIVES

Lineage-based classification has critical clinical implications in pituitary neuroendocrine tumor (PitNET). As the most prevalent subtype of multilineage PitNET, PitNET originating from both pituitary-specific positive transcription factor 1 (Pit1) and steroidogenic factor-1 (SF1) lineages (Pit1/SF1-adenoma) is expected to exhibit rich and varied clinical behaviors. A comprehensive understanding of the clinical and pathological characteristics of Pit1/SF1-adenoma will provide mechanistic insight and influence the prognosis and treatment of PitNET.

METHODS

A retrospective study was conducted by reviewing 57 cases of Pit1/SF1-adenoma between 2018 and 2022. We also included 88 cases of PitNET arising from Pit1 cell lineage (Pit1-adenoma) and 70 cases of PitNET arising from SF1 cell lineage (SF1-adenoma) as controls. Comprehensive data, including demographic, symptom, endocrinal, radiological, surgical, pathological, and prognostic information, were systematically collected. All specimens were immunostained for pituitary transcription factors (PTFs) and pituitary hormones.

RESULTS

The detection rate was 8.0% for Pit1/SF1-adenoma within PitNET surgical specimens. Pit1/SF1-adenoma displayed a male predominance, with the mean diagnosis age falling between Pit1-adenoma and SF1-adenoma. The endocrine activity of Pit1/SF1-adenoma was lower than Pit1-adenoma but higher than SF1-adenoma. Pit1/SF1-adenoma had a higher incidence of cavernous sinus invasion (56.1%) than both Pit1-adenoma (38.6%, P = .039) and SF1-adenoma (27.1%, P = .001). Furthermore, Pit1/SF1-adenoma showed more postoperative complications than Pit1-adenoma (29.8% vs 8.0%, P = .001). Nonfunctional Pit1/SF1-adenoma had a higher radiological tumor recurrence rate than nonfunctional SF1-adenoma (34.8% vs 10.9%, P = .021). Notably, the immunostaining pattern was diverse in Pit1/SF1-adenoma, with various combinations of staining intensity for PTFs and 15 combinations for 6 pituitary hormones. Intriguingly, various PTFs combinations had no different impact on the outcome of Pit1/SF1-adenoma.

CONCLUSION

Pit1/SF1-adenoma represents a unique pathological subtype of PitNET, characterized by distinctive clinical behaviors. Identifying Pit1/SF1-adenoma can facilitate more precise management of PitNET by the practical use of Pit1/SF1 immunostaining.

Pathogenesis, clinical features, and treatment of plurihormonal pituitary adenoma

Plurihormonal pituitary adenoma (PPA) is a type of pituitary tumor capable of producing two or more hormones and usually presents as an aggressive, large adenoma. As yet, its pathogenesis remains unclear. This is the first study to systematically summarize the underlying pathogenesis of PPA. The pathogenesis is related to plurihormonal primordial stem cells, co-transcription factors, hormone co-expression, differential gene expression, and cell transdifferentiation. We conducted a literature review of PPA and analyzed its clinical characteristics. We found that the average age of patients with PPA was approximately 40 years, and most showed only one clinical symptom. The most common manifestation was acromegaly. Currently, PPA is treated with surgical resection. However, recent studies suggest that immunotherapy may be a potentially effective treatment.

Applications and Integration of Radiomics for Skull Base Oncology

Radiomics, a quantitative approach to extracting features from medical images, represents a new frontier in skull base oncology. Novel image analysis approaches have enabled us to capture patterns from images imperceptible by the human eye. This rich source of data can be combined with a range of clinical features, holding the potential to be a noninvasive source of biomarkers. Applications of radiomics in skull base pathologies have centered around three common tumor classes: meningioma, sellar/parasellar tumors, and vestibular schwannomas. Radiomic investigations can be categorized into five domains: tumor detection/segmentation, classification between tumor types, tumor grading, detection of tumor features, and prognostication. Various computational architectures have been employed across these domains, with deep-learning methods becoming more common versus machine learning. Across radiomic applications, contrast-enhanced T1-weighted MRI images remain the most utilized sequence for model development. Efforts to standardize and connect radiomic features to tumor biology have facilitated more clinically applicable radiomic models. Despite the advancement in model performance, several challenges continue to hinder translatability, including small sample sizes and model training on homogenous single institution data. To recognize the potential of radiomics for skull base oncology, prospective, multi-institutional collaboration will be the cornerstone for a validated radiomic technology.

The clinical presentation of PIT1 positive pituitary neuroendocrine tumor immunonegative for growth hormone, prolactin, and thyroid stimulating hormone with analysis of clinical and immunostaining dissociation

BACKGROUND

PIT1 is a pituitary transcription factor that is associated with either growth hormone (GH), prolactin (PRL), or thyroid-stimulating hormone (TSH) production. However, PIT1-positive pituitary neuroendocrine tumors (PitNETs) are occasionally immunonegative for GH, PRL, and TSH. This paper describes the clinical presentation of PIT1 positive however immunonegative PitNETs.

METHODS

We conducted a retrospective analysis, identifying 228 PIT1-positive PitNET patients between 2017 and 2022. Out of these, ten (4%) tested negative for GH, PRL, and TSH. Functioning PitNETs were defined as those causing hormonal excess symptoms or hormonal overproduction.

RESULTS

As for 10 patients immunonegative for all three hormones however PIT1-positive, the mean ( ± standard deviation) age was 46 ± 13 years with 70% women. Six patients exhibited signs of excess GH or PRL, and three had visual problems. Additionally, one patient had secondary hypothyroidism and adrenal insufficiency resulting from the mass effect. All tumors were macroadenoma, with a median volume of 2.1 cm3 (range, 0.8-17.5 cm3). Gross total resection was attained in six patients by trans-sphenoidal surgery. Postoperatively, eight patients experienced clinical improvement: three in vision, two in amenorrhea, two in headache, and one in acromegaly symptoms. Biochemical improvement was observed in six patients, with all experiencing remission in hormonal excess and one showing improvement in secondary hypothyroidism. Stereotactic radiosurgery was performed in three patients.

CONCLUSIONS

Patients with functioning PitNETs may exhibit PIT1 staining without GH, PRL, or TSH staining. Hormonally active tumors exist in this patient population; therefore, close endocrine follow-up is necessary despite the lack of staining for GH, PRL, and TSH.

Salivary microbiome profiles for different clinical phenotypes of pituitary adenomas by single-molecular long-read sequencing

IMPORTANCE

The gut and salivary microbiomes have been widely reported to be significantly associated with a number of neurological disorders. The stability of the microbiome in the oral cavity makes it a potentially ideal sample that can be conveniently obtained for the investigation of microbiome-based pathogenesis in diseases. In the present study, we used a single-molecule long-read sequencing technique to study the distribution of the salivary microbiota in patients with pituitary adenoma (PA) and healthy individuals, as well as among four clinical phenotypes of PA. We found that the diversity of salivary microbes was more abundant in PA patients than in healthy individuals. We also observed some unique genera in different PA phenotypes. The bioinformatics-based functional predictions identified potential links between microbes and different clinical phenotypes of PA. This study improves the existing understanding of the pathogenesis of PA and may provide diagnostic and therapeutic targets for PA.

Immunohistochemical Patterns of Pituitary Adenomas in Southeastern Nigeria, a 10-year Histopathologic Review

Introduction: Pituitary adenomas [PAs] constitute the third most common primary intracranial tumours, with a wide prevalence rate of 1% to 40%. Histologic (H & E) classification into acidophilic, basophilic and chromophobic adenomas have little clinical relevance but WHO recommended immunohistochemical subclassification has both therapeutic and prognostic significance. This immunohistochemical subclassification has not been done in our environment, making it imperative for us to evaluate the patterns in our environment.Aim: To determine the immunohistochemical patterns of PAs in Southeastern Nigeria.Materials and Methods: This was a 10-year retrospective review of all PA biopsies received at University of Nigeria Teaching Hospital Enugu, Memphys Hospital for Neurosurgery Enugu and Grace Pathology Consults Enugu, Nigeria. The age, sex, histologic, immunohistochemical subtypes and biopsy size of all diagnosed PAs were analyzed using Statistical Package for Social Sciences (SPSS) version 20 (New York: IBM Inc.) and the results were expressed in descriptive statistics.Results: One hundred cases of PAs were identified in this study constituting 19.6% of all primary intracranial tumors received at our study centers during the period under review. There were 45 (45.0%) females and 55 (55.0%) males giving a female to male ratio of 1:1.2, and a mean age of 45.3 years. The commonest histologic type was acidophilic adenoma (49.0%), followed by basophilic (40.0%) and chromophobic (11.0%) adenomas. Null cell adenomas were the most common immunohistochemical subtype (44.0%), followed by PRL-secreting adenomas (27.0%). Others were Luteinizing hormone (LH) - 13 (13.0%), follicle stimulating hormone (FSH) - 7 (7.0%), growth hormone (GH) - 3(3.0%), TSH - 2(2.0%) and ACTH - 1(1.0%) adenomas.Conclusion: PAs predominate amongst males, occurring mostly in the middle age groups in Southeastern Nigeria. Null cell adenoma is the commonest immunohistochemical subtype followed by PRL-secreting adenomas. Routine immunohistochemical characterization is required for accurate diagnosis and optimal patient care.

Primary Pituitary Carcinoids Do Not Exist: A Reappraisal in the Era of Pituitary Neuroendocrine Tumours

The World Health Organization classification of pituitary tumours, published in 2022, supported a change in the terminology from "pituitary adenoma" to "pituitary neuroendocrine tumour" (PitNET). The neuroendocrine cells represent an integral part of the diffuse neuroendocrine system, including, among others, thyroid C cells, the parathyroid chief cells, and the anterior pituitary. Normal and neoplastic adenohypophyseal neuroendocrine cells have light microscopic, ultrastructural features and an immunoprofile compatible with the neuroendocrine cells and neuroendocrine tumours from other organs. Moreover, neuroendocrine cells of pituitary origin express transcription factors which indicate their cell-lineage origin. Thus, pituitary tumours are now considered as a continuum with other neuroendocrine tumours. PitNETs may occasionally be aggressive. In this context, the term "pituitary carcinoid" has no specific meaning: it either represents a PitNET, or a metastasis to the pituitary gland of a neuroendocrine tumour (NET). An accurate pathological evaluation, combined where necessary with functional radionuclide imaging, can define the origin of the tumour. We recommend that clinicians liaise with patient groups to understand the terminology to define primary tumours of adenohypophyseal cells. It is incumbent upon the responsible clinician to explain the use of the word "tumour" in a given clinical context.

Clinical and prognostic significance of granulation patterns in somatotroph adenomas/tumors of the pituitary: a meta-analysis

INTRODUCTION

Sparsely granulated somatotroph adenoma/tumor (SGST) is thought to be more clinically aggressive than densely granulated somatotroph adenoma/tumor (DGST). However, the literature is not entirely consistent as to the disparate demographic and behavioral features of these subtypes. In this study, we conducted a meta-analysis to further clarify the demographic, clinicopathological, prognostic, and molecular characteristics of SGST versus DGST.

METHODS

We accessed two electronic databases to search for potential data. Pooled estimates of odds ratio (OR), mean difference (MD), and corresponding 95% confidence interval (CI) were calculated using the random-effect model.

RESULTS

SGST was associated with younger patient age and lower male-to-female ratio (p < 0.001) compared to DGST. Clinically, SGST had larger tumor size and high rate of cavernous sinus and suprasellar extension (p < 0.001) than DGST. During postoperative follow-up, SGST was associated with a lower endocrinological remission rate (OR 0.60; 95% CI 0.40 to 0.90; p = 0.01) and a poorer response rate to SRL (OR 0.16; 95% CI 0.08-0.35; p < 0.001) in comparison to DGST. The prevalence of GSP mutations was significantly lower in SGST (OR 0.36; 95% CI 0.17 to 0.79; p = 0.01).

CONCLUSION

SGST and DGST were demographically, clinicopathologically, and molecularly different from each other with the former associated with adverse treatment outcomes and poor response to medical therapy. There are still gaps in translational studies that could help us better understand the behavior of these tumors and identify potential targets in the treatment of sparsely granulated tumors.

Pharmacological Treatment of Non-Functioning Pituitary Adenomas

Treatment strategies for NFPA include surgery, radiotherapy, medical treatment, or follow-up. The treatment of NFPAs with compressive symptoms is surgical. However, in case of post-surgical tumor remnants, there may be treatment strategies that include observation and radiotherapy. Recently, medical treatment with cabergoline (CAB) has been recommended to contain and/or reduce the size of the tumor remnant. Based on the findings that many NFPAs show a dopamine receptor (DR) and somatostatin receptor (SR) expression, medical therapy with dopamine agonists (DAs) and somatostatin receptor ligands (SSRLs) has been tested as an alternative to prevent recurrence after surgery. The DAs have been the most extensively studied, showing some potential in terms of tumor shrinkage. SSRLs and other emerging medical options are much less studied. We will review and critically evaluate the current data on the medical therapy of NFPAs to elucidate their role in the management of this tumor type. In the case of actively growing remnants (more than 10% growth per year) and high-risk pituitary adenomas, treatment with CAB at a dose of 1.5-3.0 mg is indicated for tumor containment and/or reduction. In relation to combined chemotherapy with CAB, there is little information in the literature to support its use. In our experience, CAB treatment can be used after radiotherapy as an adjuvant treatment.