The oculomotor cistern and pituitary adenomas: anatomical and clinical study.

OBJECTIVE: The oculomotor cistern (OMC) is a meningeal cuff filled with CSF that contains the oculomotor nerve (cranial nerve [CN] III) at the level of the lateral wall of the cavernous sinus. Only a few studies have investigated the involvement of the OMC by pituitary adenomas (pituitary neuroendocrine tumors [PitNETs]), mainly with relatively small case series. The aim of this study was to perform a histomorphological description of the OMC and systematically analyze its involvement by PitNETs from radiological, clinical, and surgical perspectives. METHODS: Ten hemisellae from formalin-fixed specimens were studied with 3-µm sections. Digital image analysis software was used for morphological and quantitative assessments. Clinical, radiological, surgical, and histological data of patients undergoing endoscopic transsphenoidal surgery for PitNETs at the University of Brescia, Italy, between 2014 and 2021 were recorded. OMC involvement was graded as not compressed, compressed, and invaded. The same surgical team operated on all patients. RESULTS: The OMC had an elliptical shape with an average area of 3.1 mm2 and a length of 5.5 mm. No cisternal points of weakness were recognized in the histomorphological study. Of 315 patients, 246 had complete data: apoplexy and CN III palsy were documented in 6.9% and 8.5%, respectively. OMC compression and invasion were recorded in 106 (43.1%) and 23 (9.3%) patients. Significant associations between OMC involvement and PitNET dimensions (p < 0.001), Knosp grade (p < 0.001), preoperative oculomotor palsy (p < 0.001), Ki-67 percentage (p = 0.009), and recurrence/progression of residual tumor (p = 0.008) were found. A new postoperative CN III palsy was evident in 2%: transient in 4 cases, and persistent in 1 patient treated for a recurrent PitNET who experienced a local infection complication. Preoperative CN III palsy improved in 10 cases. CONCLUSIONS: Significant OMC involvement by PitNETs might be underrecognized, but it can be treated using the endoscopic transsphenoidal approach, and it affects patient outcomes.

Mixed thyrotropin-secreting pituitary neuroendocrine tumor coexisting with Graves' disease: a case report.

Background: Thyrotropin (TSH)-secreting pituitary neuroendocrine tumors (PitNETs) are recognized as a rare disease. Mixed TSH PitNETs account for 20-25% of TSH PitNETs. This study aimed to report an extremely rare case of a mixed TSH PitNET coexisting with Graves' disease (GD) and also to review the literature. Case presentation: A 36-year-old male patient presented with elevated levels of free triiodothyronine (FT3), free thyroxine (FT4), and insulin-like growth factor 1 (IGF-1) but a non-suppressed thyroid-stimulating hormone (TSH) level. His anti-thyroglobulin antibody (TgAb), anti-thyroid peroxidase autoantibody (TPOAb), and thyrotropin receptor antibody (TRAb) tests were positive. Symptoms of palpitations, hyperhidrosis, heat intolerance, and irritability appeared 2 years before his admission. However, he showed neither any signs nor any symptoms of acromegaly. The contrast-enhanced pituitary magnetic resonance imaging (MRI) showed enlargement of the pituitary fossa, with an irregular abnormal signal mass. The patient underwent endoscopic pituitary tumor resection via a transsphenoidal approach. The postoperative pathology suggested a mixed pituitary adenoma. At 8 months after the surgery, the patient had a postoperative recurrence of hyperthyroidism, and methimazole (MMI) was then administered. The recurrence of the TSH PitNET was confirmed by the positron emission tomography-computed tomography (PET-CT), which was performed 11 months after the surgery, and treatment with lanreotide was initiated. Gradually, his levels of FT3, FT4, TSH, TPOAb, and TgAb became normal and the levels of TRAb and IGF-1 improved. Conclusion: When the circulating levels of both FT4 and FT3 were upregulated, non-suppressed TSH levels and positive thyroid antibodies were found. TSH PitNETs coexisting with GD should be carefully taken into account to avoid the potential risk of treatment-induced tumor progression.

Clinico-radio-pathological predictors of outcomes in patients with acromegaly undergoing endoscopic transsphenoidal surgery.

Background: Acromegaly is a rare chronic endocrine disorder with variable biochemical remission rates from 40% to 85%. Hence, understanding the factors predicting biochemical cures helps in planning targeted and personalized treatment. We aimed to study the various clinico-radio-pathological predictors of outcomes in patients with pituitary neuroendocrine tumor (PitNET) who underwent transsphenoidal surgery (TSS) at 3 months follow-up. Methods: Our cohort included 61 consecutive patients with acromegaly treated at an institute in northwest India between January 2019 and June 2021. The outcomes of TSS were assessed at the end of 3 months postoperatively as defined by Endocrine Society Guidelines 2014. Results: The mean age at diagnosis was 38 ± 12 years, with the majority being females (67.2%). The median tumor volume was 2376 mm3 with high insulin-like growth factor-1 levels (3.12 ± 1.76 times the upper reference limit). Forty-two patients (68.8%) had radiological evidence of cavernous sinus invasion. Overall, the biochemical remission rate at 3 months was 34.4%. Unlike preoperative Knosp grading, T2-hypointensity was not predictive of biochemical remission. The granularity of PitNET, as well as immunohistochemical (IHC) markers such as Ki-67 index somatostatin receptor subtype (SSTR2/5) and low-molecular-weight cytokeratin (CAM5.2) expression, failed to show any significant correlation with remission. Conclusion: Overall, bulky tumors, higher hormone burden, and advanced Knosp grades translated to lower rates of biochemical remission in the present study cohort. Contrary to earlier studies, conventional IHC markers such as Ki-67, SSTR2/5, and CAM5.2 were not useful for predicting biochemical remission at 3 months.

The 2022 WHO classification of tumors of the pituitary gland: An update on aggressive and metastatic pituitary neuroendocrine tumors.

The vast majority of pituitary neuroendocrine tumors (PitNETs) are benign and slow growing with a low relapse rate over many years after surgical resection. However, about 40% are locally invasive and may not be surgically cured, and about one percentage demonstrate an aggressive clinical behavior. Exceptionally, these aggressive tumors may metastasize outside the sellar region to the central nervous system and/or systemically. The 2017 (4th Edition) WHO Classification of Pituitary Tumors abandoned the terminology "atypical adenoma" for tumors previously considered to have potential for a more aggressive behavior since its prognostic value was not established. The 2022 (5th Edition) WHO Classification of the Pituitary Tumors emphasizes the concept that morphological features distinguish indolent tumors from locally aggressive ones, however, the proposed histological subtypes are not consistent with the real life clinical characteristics of patients with aggressive tumors/carcinomas. So far, no single clinical, radiological or histological parameter can determine the risk of growth or malignant progression. Novel promising molecular prognostic markers, such as mutations in ATRX, TP53, SF3B1, and epigenetic DNA modifications, will need to be verified in larger tumor cohorts. In this review, we provide a critical analysis of the WHO guidelines for prognostic stratification and diagnosis of aggressive and metastatic PitNETs. In addition, we discuss the new WHO recommendations for changing ICD-O and ICD-11 codes for PitNET tumor behavior from a neoplasm either "benign" or "unspecified, borderline, or uncertain behavior" to "malignant" neoplasm regardless of the clinical presentation, histopathological subtype, and tumor location. We encourage multidisciplinary initiatives for integrated clinical, histological and molecular classification, which would enable early recognition of these challenging tumors and initiation of more appropriate and aggressive treatments, ultimately improving the outcome.

Research progress on nonsteroidal anti-inflammatory drugs in the treatment of pituitary neuroendocrine tumors.

Pituitary neuroendocrine tumor is the third most common primary intracranial tumor. Its main clinical manifestations include abnormal hormone secretion symptoms, symptoms caused by tumor compression of the surrounding pituitary tissue, pituitary stroke, and other anterior pituitary dysfunction. Its pathogenesis is yet to be fully understood. Surgical treatment is still the main treatment. Despite complete resection, 10%-20% of tumors may recur. While dopamine agonists are effective in over 90% of prolactinomas, prolonged use and individual variations can lead to increased drug resistance and a gradual decline in efficacy, which ultimately requires surgical intervention. Nonsteroidal anti-inflammatory drugs reduce the production of inflammatory mediator prostaglandins by inhibiting the activity of cyclooxygenase and exert antipyretic, analgesic, antiplatelet, and anti-inflammatory effects. In recent years, many in-depth studies have confirmed the potential of nonsteroidal anti-inflammatory drugs as a preventive and antitumor agent. It has been extensively utilized in the prevention and treatment of various types of cancer. However, their specific mechanisms of action still need to be fully elucidated. This article summarizes recent research progress on the expression of cyclooxygenase in pituitary neuroendocrine tumors and the treatment of nonsteroidal anti-inflammatory drugs. It provides a feasible theoretical basis for further research on pituitary neuroendocrine tumors and explores potential therapeutic targets.

Collision of pituitary neuroendocrine tumor and anterior clinoid meningioma treated with a two-stage minimally invasive surgical strategy: illustrative case.

BACKGROUND: The locations of pituitary neuroendocrine tumor (PitNET) and anterior clinoid meningioma (ACM) appear to be very close but essentially different, as the former is inside the sella turcica while the latter is in the intradural space. A collision tumor thus requires a specific treatment strategy but has been rarely reported. OBSERVATIONS: A 77-year-old woman presented with progressive visual impairment due to significant compression of the optic apparatus by a collision of PitNET and ACM. With a minimally invasive two-stage therapeutic strategy, the ACM was first resected using an endoscopic mini-pterional approach, then the PitNET was removed with an endoscopic transnasal approach 8 weeks later, leading to significant improvement in visual function. The authors' literature search identified only 2 documented cases of a similar collision. LESSONS: This case underscores the complexity of the decision-making process in the management of collision tumors and suggests the potential benefit of staged minimally invasive surgical interventions in preserving visual function. Further accumulation of cases is warranted for refining the treatment strategy. https://thejns.org/doi/10.3171/CASE24240.

Outcome of endoscopic transsphenoidal surgery for acromegaly: Comparison of using and not using the floor standing pneumatic powered endoscope-holder system.

Introduction: Endoscopic transsphenoidal surgery can be performed by two surgeons, including an endoscopist (PE/2S), and by a single surgeon with an endoscope-holder system (PE/1S + H). We analyzed the surgical outcome, and outcome predictors in acromegaly patients in endoscopic transsphenoidal surgery using floor standing pneumatic endoscope-holder system. Methods: Endoscopic transsphenoidal surgery was performed with PE/1S+H (n = 51) and PE/2S (n = 20). Postoperative remission was evaluated by the 2010 consensus criteria for acromegaly. We compared the surgical results of PE/2S style and PE/1S+H style, and investigated the factors associated with favorable surgical outcomes. Results: There was no difference in clinical background between the PE/2S and the PE/1S + H groups. The remission rates for PE/2S and PE/1S+H were 65.0% and 82.4%, respectively, with no significant difference (p = 0.128). In consecutive 71 cases, statistically useful predictors of remission were low preoperative growth hormone (GH) level (<12 ng/mL), low Knosp grade (0-2), and low revised Knosp grade (0-3A). In the conventional Knosp grade 0-2 and 3/4, the sensitivity was 0.76 and the specificity was 0.81. In the revised Knosp grade 0-3A and 3B/4, the sensitivity was 0.96 and the specificity was 0.44. Conclusion: The outcome of GH-producing pituitary neuroendocrine tumors surgically removed by PE/1S+H could be almost equivalent to that by PE/2S. Preoperative low GH level and Knosp grades, including revised Knosp grades, are useful preoperative predictors for surgical remission of acromegaly.

Pseudocapsular resection to prevent recurrence in nonfunctioning pituitary neuroendocrine tumors: a retrospective, single-center study with more than 5 years of follow-up.

OBJECTIVE: Pseudocapsular resection is a well-recognized, useful approach to achieve endocrinological remission in functioning pituitary neuroendocrine tumors (PitNETs). However, its advantage in nonfunctioning PitNETs (NF-PitNETs) has not been established. This study aimed to clarify the contribution of pseudocapsular resection to the prevention of NF-PitNET recurrence in long-term follow-up. METHODS: This retrospective study included 132 patients who underwent total tumor removal and were followed for more than 5 years after surgery. The patients were categorized into those who underwent total pseudocapsular resection (n = 67) and those who did not (n = 65). The nonpseudocapsule (nonpseudocap) resection group included patients who underwent partial pseudocapsular resection and those in whom the pseudocapsule was not resected, did not exist, or could not be identified during surgery. The main outcome measures were the tumor recurrence rate and site of recurrence. RESULTS: In the nonpseudocap resection group, 2 patients (3.1%) had tumor recurrence in the cavernous sinus and 5 (7.7%) had tumor recurrence in the pituitary fossa. In the pseudocapsule (pseudocap) resection group, only 2 patients (3.0%) had tumor recurrence in the cavernous sinus and 0 patients had tumor recurrence in the pituitary fossa. Tumor recurrence in the pituitary fossa was more likely to occur in the nonpseudocap resection group than in the pseudocap resection group (p = 0.0267). Multivariate regression analysis revealed that pseudocapsular resection was a significant factor for reducing the tumor recurrence rate in the pituitary fossa (p = 0.0107). CONCLUSIONS: Pseudocapsular resection may reduce the rate of tumor recurrence and improve the management of NF-PitNETs in long-term follow-up.

Silent Corticotroph Adenomas Demonstrate Predilection for Sphenoid Sinus, Cavernous Sinus, and Clival Invasion Compared with Other Subtypes.

BACKGROUND: Nonfunctional pituitary neuroendocrine tumors (PitNETs) exhibit wide variability in growth pattern based on subtype. Silent corticotroph adenomas (SCAs) demonstrate aggressive growth compared with other nonfunctional pituitary adenomas (NFPAs), especially into the cavernous sinus. In this study, we sought to characterize other growth patterns of SCAs compared with NFPAs. METHODS: We performed a retrospective analysis of all patients with nonfunctional PitNETs treated with surgical resection via endoscopic endonasal approach at a single institution from August 1, 2018, to May 11, 2024. Preoperative computed tomography and magnetic resonance imaging were reviewed to determine extension into the suprasellar space, sphenoid sinus, cavernous sinus, and clivus. RESULTS: The study comprised 91 patients, including 20 SCAs and 71 NFPAs. SCAs demonstrated significantly greater rates of growth into the sphenoid sinus (55.0% vs. 23.94%, P = 0.013), clivus (65.0% vs. 16.9%, P < 0.0001), and cavernous sinus (defined as Knosp grade 3 or 4; 55.0% vs. 23.35%, P = 0.016). Other NFPAs were more likely to grow into the suprasellar space (92.96% vs. 75.0%, P = 0.038). Tumor volume was similar between groups (11.93 cm3 vs. 9.06 cm3, P = 0.2). CONCLUSIONS: Silent corticotroph PitNETs demonstrate predilection for invasion of bony structures, with higher rates of growing through the sellar floor into the sphenoid sinus, growing posteroinferiorly into the clivus and laterally into the cavernous sinuses. Other nonfunctional PitNETs tended to follow the path of least resistance, growing superiorly into the suprasellar space. These differences in growth patterns may account for some of the clinical challenges of treating silent corticotroph PitNETs.

Characteristics and treatment of a silent somatotroph tumor that had transformed to a functional type: a case report and literature review.

Background: "Functionalization" of silent pituitary neuroendocrine tumors (PitNETs) is a pretty rare clinical phenomenon that reportedly occurs most often with silent corticotroph tumors (SCTs). We report the case of silent somatotroph tumor (SST) that had transformed to functional type. We also review similar cases of SST with functionalization. Case Description: A 43-year-old man without suggestive symptoms of a pituitary tumor was referred with a lesion in the sellar region detected incidentally. Serum insulin-like growth factor 1 (IGF-1) (348 ng/mL) was high, whereas growth hormone (GH) was within the normal range. A glucose GH inhibition test showed inhibition of GH to 0.4 ng/mL. Subtotal tumorectomy was performed via a transnasal-sphenoidal approach. Histopathological examination of the operative specimen showed weak expression of GH and diffuse staining of pituitary-specific transcription factor-1 (Pit-1). The final pathological diagnosis was SST. Five years after the first surgery without follow-up, the patient presented again because of headache, impaired vision, bone pain, and high blood glucose concentrations for 2 months. Physical examination showed early acromegalic features. Of interest, greatly increased concentrations of GH (7.2 ng/mL) and IGF-1 (533 ng/mL) were found. Magnetic resonance imaging showed the recurrence of tumor. A diagnosis of acromegaly was considered. The patient underwent a second transsphenoidal pituitary tumor resection, after which his serum GH and IGF-1 concentrations decreased. Unlike the original surgical specimen, immunohistochemical examination of the tissue resected during the second surgery showed strong GH positivity, with similarly strong Pit-1 positivity. The patient was followed up for 6 months without octreotide treatment. At the last follow-up, he was found to have high serum concentrations of GH and IGF-1, which demonstrated another progression of the remnant PitNET. After two courses of octreotide acetate microspheres (20 mg/month), the acromegaly was under control. Conclusions: In addition to SCTs, other silent PitNETs could also functionalize. Medical teams of PitNETs should recognize this rare phenomenon and conduct long-term follow-up. After functionalization, these tumors have a high recurrence rate, requiring multiple therapies and long-term follow-up. Further research is essential to determine the mechanism of regulation of secretion of GH by such tumors.

Neuronavigation-assisted pituitary neuroendocrine tumor resection: a systematic review and meta-analysis.

Background: The advancement of pituitary surgery has rendered it a secure and efficient treatment method; nevertheless, the potential for incomplete tumor removal and cerebrospinal fluid (CSF) leak remains. Neuronavigation-assisted pituitary neuroendocrine tumor (PitNET) resections have been driving a rising number of attentions in recent years. However, there is currently a lack of comprehensive quantitative evaluation of the effectiveness of neuronavigation-assisted pituitary tumor resection. We aimed to assess the curative effects and complications with or without the use of an image-based neuronavigation in PitNET resection. Methods: A systematic review and meta-analysis was performed by searching PubMed, EMBASE, Cochrane Library, Web of Science, and Scopus from inception until May 1, 2024 in English to identify any studies reporting gross total resection (GTR) or postoperative complications in patients who underwent neuronavigation-assisted PitNET resection, excluding conference abstracts and studies with fewer than five subjects. We also searched the reference lists of previous systematic reviews and other relevant publications in databases. We reviewed and analyzed the studies that investigated the operative effects and complications of neuronavigation in PitNET resection. Study quality was assessed by the Newcastle-Ottawa scale, and publication bias was evaluated by funnel plot. Review manager 5.3 was employed for meta-analysis. The results were expressed as odds ratio (OR) with 95% confidence interval (CI) of image-assisted techniques for the incidence of GTR and complications. Results: A total of 42 publications that fulfilled the established searching criteria were obtained from the above-mentioned databases, all of which with the Newcastle-Ottawa Scale scores ≥ six ★. Among the included publications, 37 studies indicated that the OR of image-based neuronavigation was 2.29 (95% CI: 2.02-2.60, P<0.00001, I2=24%) for GTR. The other five studies compared the neuronavigation group (experimental group) and non-neuronavigation group (control group), exhibiting high heterogeneity (I2=91%). After sensitivity analysis, the results showed that the rate of the CSF leak of the neuronavigation group was slightly lower than that of the non-neuronavigation group (OR: 0.84, 95% CI: 0.73-0.97, P=0.01, I2=43%). Conclusions: According to the existing data, neuronavigation-assisted PitNET resection can increase the rates of GTR and reduce the incidence of postoperative complications. Our results provide a reference for the selection of surgical methods for PitNET resection in future clinical practice.

Treatment of an Aggressive Gonadotroph Pituitary Neuroendocrine Tumor With 177Lutetium DOTATATE Radionuclide Therapy.

Aggressive pituitary neuroendocrine tumors (PitNETs) present significant morbidity, and multimodal therapies including surgery, radiotherapy, and medications are frequently required. Chemotherapy, particularly temozolomide, is often pursued for tumors that progress despite these treatments. Although peptide receptor radionuclide therapy (PRRT) using radiolabeled somatostatin analogs is approved for the treatment of well-differentiated gastrointestinal neuroendocrine tumors, its use in aggressive PitNETs is limited. We describe the case of a 65-year-old man who presented with vision changes and hypopituitarism at age 33 secondary to a nonfunctioning gonadotroph PitNET. His initial treatment included a craniotomy followed by radiation therapy. With tumor regrowth, he required transsphenoidal surgeries at age 44 and age 52. At age 56, further tumor regrowth and a positive octreotide scan prompted treatment with long-acting octreotide for 1 year. Given absent tumor response, 12 cycles (4 treatment cycles and 8 maintenance cycles) of PRRT with 177Lutetium-DOTATATE were pursued. This resulted in partial response with significant tumor shrinkage. Notably, there was no tumor regrowth 40 months after treatment discontinuation. This is only the second report on the effectiveness of PRRT in patients with aggressive gonadotroph PitNETs. We also provide an overview of PRRT for PitNETs and describe clinical outcomes previously reported in the literature.

Single-Cell RNA Sequencing and Its Applications in Pituitary Research.

BACKGROUND: Mounting evidence underscores the significance of cellular diversity within the endocrine system and the intricate interplay between different cell types and tissues, essential for preserving physiological balance and influencing disease trajectories. The pituitary gland, a central player in the endocrine orchestra, exemplifies this complexity with its assortment of hormone-secreting and nonsecreting cells. SUMMARY: The pituitary gland houses several types of cells responsible for hormone production, alongside nonsecretory cells like fibroblasts and endothelial cells, each playing a crucial role in the gland's function and regulatory mechanisms. Despite the acknowledged importance of these cellular interactions, the detailed mechanisms by which they contribute to pituitary gland physiology and pathology remain largely uncharted. The last decade has seen the emergence of groundbreaking technologies such as single-cell RNA sequencing, offering unprecedented insights into cellular heterogeneity and interactions. However, the application of this advanced tool in exploring the pituitary gland's complexities has been scant. This review provides an overview of this methodology, highlighting its strengths and limitations, and discusses future possibilities for employing it to deepen our understanding of the pituitary gland and its dysfunction in disease states. KEY MESSAGE: Single-cell RNA sequencing technology offers an unprecedented means to study the heterogeneity and interactions of pituitary cells, though its application has been limited thus far. Further utilization of this tool will help uncover the complex physiological and pathological mechanisms of the pituitary, advancing research and treatment of pituitary diseases.

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.

[Aggressive pituitary tumors and carcinomas: modern classification, advances and prospects in treatment]. / Agressivnye opukholi i kartsinomy gipofiza: sovremennaya klassifikatsiya, dostizheniya i perspektivy v lechenii.

Despite slow growth of most pituitary tumors and high rates of total resection and/or effective therapy, pituitary neoplasms are characterized by aggressive behavior with high growth rate, frequent relapses and resistance to standard treatments in 10% of cases. In modern WHO classifications of tumors of the central nervous system, endocrine and neuroendocrine tumors, the authors propose the definition «pituitary neuroendocrine tumor¼ instead of previous «pituitary adenoma¼ and «metastasizing pituitary neuroendocrine tumor¼ instead of «pituitary carcinoma¼. Currently, there are no effective prognostic markers of aggressive tumors. This complicates early diagnosis. It is proposed to apply a five-stage prognostic classification based on proliferation rate (including mitotic count, Ki-67 index and p53 immunoexpression) and morphometric markers of invasiveness for all resected pituitary neoplasms. This approach would be valuable for earlier detection of aggressive tumors and pituitary carcinomas. Compression of visual pathways, third ventricle and brain stem due to rapid growth of aggressive tumors usually requires redo surgeries with subsequent radiotherapy. Hormonally active tumors require therapy with somatostatin analogues and dopamine agonists in maximum possible doses. Chemotherapy with temozolomide as first-line option is recommended if standard treatment is ineffective. Alternative treatment includes peptide receptor radionuclide therapy (PRRT), molecular targeted therapy (bevacizumab, tyrosine kinase inhibitors, everolimus and cyclin-dependent kinase inhibitors) and immunotherapy (checkpoint inhibitors). Considering the need for combined treatment, these cases should always be discussed by a multidisciplinary team (neurosurgeon, endocrinologist, radiotherapist, oncologist, pathologist) with necessary qualifications and experience in treating these patients. Treatment of aggressive tumors and pituitary carcinomas is becoming an active and rapidly developing direction in neurosurgery, endocrinology and oncology.

Mixed pituitary adenoma/pituitary neuroendocrine tumor-gangliocytoma: Immunohistochemical insights.

Mixed pituitary adenoma/PitNET-gangliocytomas (PA/PitNET-GC) have been reported in small series over the past 20 years; some had limited immunohistochemistry (IHC) data. We interrogated our experience over 20 years, focusing on patterns of the GC component and IHC results for anterior pituitary hormones, transcription factors, NFP, and CAM5.2. A search of cases from 2002 to 2023 yielded 20 cases: 7M:13F, ages 20-71 years; 17 macroadenomas, 1 microadenoma, 2 ectopic. GC was co-associated with 4 corticotroph, 2 densely granulated lactotroph, 5 mixed lactotroph-somatotroph, 1 immature PIT1-lineage tumor, and 8 sparsely granulated GH; the latter all had a minor lactotroph component. Patterns were: discrete nodular foci of GC (9/20), extensive GC differentiation often overshadowing the PA/PitNET (7/20), and intimate admixture of smaller bands of neuropil and individual metaplastic ganglion cells within PA/PitNET (4/20). NFP highlighted small cohesive regions of neuropil and identified greater axonal content, including individual axons within "pure" PA/PitNET areas, than appreciated on H&E. CAM5.2 IHC often revealed cells with neuronal morphologies to a greater extent than NFP and in different areas within the same tumor. These data suggest that the combined use of NFP and CAM5.2 IHC best reveals transition from PA to GC phenotype, with CAM5.2 positivity reflecting earlier stages of transformation.

Apoplexy of a giant clival ectopic prolactinoma: A very rare case report.

INTRODUCTION AND IMPORTANCE: Ectopic pituitary neuroendocrine tumor (EPNET) is a very rare entity, seldom with apoplexy evolution. Only three cases of intracranial ectropic pituitary neuroendocrine tumor apoplexy were reported in the literature. CASE PRESENTATION: We report the case of a 45-year-old woman with a history of amenorrhea, and headaches. Neuroimaging showed a very aggressive giant mass within the clivus with the invasion of the sphenoidal sinus and encasement of internal carotid arteries with an empty sella. Endocrinology work-up revealed an exceedingly high level of prolactin surprisingly without galactorrhea. Immunohistochemical analysis after an endonasal biopsy confirmed the diagnosis of prolactinoma. One month after Cabergoline initiation, an apoplexy of the ectopic pituitary neuroendocrine tumor occurred. Conservational management with a decrease in cabergoline dose was performed. DISCUSSION: This article highlights data from various cases reported in the literature in addition to our case to confirm the extreme rarity of apoplexy as a complication of EPNET. CONCLUSION: Pituitary apoplexy in ectopic pituitary neuroendocrine tumor is extremely rare. Therefore, in case of unusual localization of pituitary neuroendocrine tumor, a thorough follow-up is necessary to detect complications and ensure early management.

Pituitary neuroendocrine tumors and granular cell pituicytomas at autopsy: Incidence, cell types, locations, and histogenesis in 150 pituitary glands.

OBJECTIVES: The incidence of pituitary neuroendocrine tumors has been reported high at autopsy. This study aimed to detect many tumors in both anterior and posterior lobes to prove tumor histogenesis. METHODS: In total, 150 pituitary glands were studied from the University of Kansas Medical Center from 1995 to 2000. The pituitary gland was sagittally sliced from anterior to posterior into 6 to 8 sections. When H&E-stained sections revealed tumors, the tumors were immunohistochemically stained for 6 pituitary hormones. RESULTS: Among 150 autopsy cases, 38 (25.3%) harbored microadenomas, including 4 cases with double tumors. Twenty-three (54.7%) cases were negative to all pituitary hormones. Of the remaining 19 tumors, 13 (30.9%) were lactotrophs, with 4 cases being concomitantly somatotrophs and gonadotrophs, and 2 cases were corticotropes. More than 85% of pituitary neuroendocrine tumors were adjacent to the capsule. Thirteen (8.7%) granular cell pituicytomas were found in the posterior lobe. There were pituicytes transforming into granular cell tumors. CONCLUSIONS: The incidence was 25.3% for pituitary neuroendocrine tumors and 8.7% for granular cell pituicytomas. Since most pituitary neuroendocrine tumors were adjacent to the pituitary capsule, the capsule appeared to be the germinal center. Both pituitary tumors belonged to the 2 different transcription factor lineages.

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.

Analysis of MRI features and associated factors of the pituitary neuroendocrine tumor streaky sign.

OBJECTIVES: Observation of pituitary neuroendocrine tumors with streaky sign on MRI, analysis of their features on imaging and further investigation of the relationship between the direction of the streak sign and the direction of optimal tumor expansion. METHODS: The MR images of 237 patients with pituitary neuroendocrine tumors were retrospectively analyzed. The streaky-like high signal with a substantial length of more than 10 mm and obvious enhancement on T1WI was defined as the streaky sign. Finally, 66 patients were included in the study, comprising 33 patients with streaky sign pituitary neuroendocrine tumors and 33 randomly selected patients with non-streaky sign pituitary neuroendocrine tumors. The general condition of these 66 patients, the imaging features of the tumor, and the measurement and analysis of the direction of the streaky sign in relation to the direction of optimal tumor extension were observed and analyzed. RESULTS: On MRI, 85 streaky signs were observed. The average deviation between the direction angle of all the streaky signs and the optimal extension direction angle of the tumor was approximately 11°. The longest streaky sign angle was positively correlated with the optimal extension angle of the tumor, with a correlation coefficient of 0.967. CONCLUSION: The presence of a streaky sign of pituitary neuroendocrine tumors may indicate a dilated sinus or a small blood vessel. Its direction is highly consistent with the optimal extension direction of the tumor, which has a certain supporting effect on the long-distance growth of the tumor.