Pathology of invasive pituitary tumors with special reference to functional classification

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.

Cabergoline-induced cerebrospinal fluid fistulae in macroprolactinomas

PURPOSE

Cerebrospinal fluid (CSF) rhinorrhea is a rare complication after dopamine agonist treatment of macroprolactinomas. Up to 90% need surgical repair, however, there are controversial opinions on the necessity of tumor resection upon this occasion. Here we present our long-term follow-up experience in patients who underwent surgical repair of the CSF leak or observation.

METHODS

We report a series of three patients who presented with cabergoline-induced CSF rhinorrhea with long-term follow-up up to 170 months. Two patients underwent endoscopic transnasal-transsphenoidal surgical repair of CSF rhinorrhea by fat graft and fibrin glue without tumor removal. In another patient, CSF rhinorrhea resolved spontaneously after two weeks without recurrence.

RESULTS

All three patients had no recurrence of CSF rhinorrhea during long-term follow-up up to 170 months. One patient with surgical CSF leak repair was asymptomatic with continued medication at long-term follow-up of 116 months. Tumor progression occurred 21 months after CSF leakage repair in another patient after cessation of dopamine agonist treatment and necessitated tumor debulking. The patient with continued medication without surgery had no recurrence of CSF rhinorrhea on long-term follow-up of 170 months.

CONCLUSION

The optimal management of CSF fistulae due to tumor shrinkage of macroprolactinomas after dopamine agonist therapy remains to be defined. Exceptionally, medication-induced CSF fistulae in response to tumor shrinkage may close spontaneously without recurrence. If persistent, transnasal-transsphenoidal closure of CSF fistulae represents an efficient treatment and dopamine agonist treatment may be continued. Thus, we recommend early surgical repair.

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.

CD87-targeted BiTE and CAR-T cells potently inhibit invasive nonfunctional pituitary adenomas

Recently, bispecific T-cell engagers (BiTEs) and chimeric antigen receptor-modified T cells (CAR-Ts) have been shown to have high therapeutic efficacy in hematological tumors. CD87 is highly expressed in solid tumors with an oncogenic function. To assess their cytotoxic effects on invasive nonfunctioning pituitary adenomas (iNFPAs), we first examined CD87 expression and its effects on the metabolism of iNFPA cells. We generated CD87-specific BiTE and CAR/IL-12 T cells, and their cytotoxic effects on iNFPAs cells and in mouse models were determined. CD87 had high expression in iNFPA tissue and cell samples but was undetected in noncancerous brain samples. CD87×CD3 BiTE and CD87 CAR/IL-12 T-cells showed antigenic specificity and exerted satisfactory cytotoxic effects, decreasing tumor cell proliferation in vitro and reducing existing tumors in experimental mice. Overall, the above findings suggest that CD87 is a promising target for the immunotherapeutic management of iNFPAs using anti-CD87 BiTE and CD87-specific CAR/IL-12 T cells.

The regulatory role and clinical application prospects of circRNA in the occurrence and development of CNS tumors

BACKGROUND

Central nervous system (CNS) tumors originate from the spinal cord or brain. The study showed that even with aggressive treatment, malignant CNS tumors have high mortality rates. However, CNS tumor risk factors and molecular mechanisms have not been verified. Due to the reasons mentioned above, diagnosis and treatment of CNS tumors in clinical practice are currently fraught with difficulties. Circular RNAs (circRNAs), single-stranded ncRNAs with covalently closed continuous structures, are essential to CNS tumor development. Growing evidence has proved the numeral critical biological functions of circRNAs for disease progression: sponging to miRNAs, regulating gene transcription and splicing, interacting with proteins, encoding proteins/peptides, and expressing in exosomes.

AIMS

This review aims to summarize current progress regarding the molecular mechanism of circRNA in CNS tumors and to explore the possibilities of clinical application based on circRNA in CNS tumors.

METHODS

We have summarized studies of circRNA in CNS tumors in Pubmed.

RESULTS

This review summarized their connection with CNS tumors and their functions, biogenesis, and biological properties. Furthermore, we introduced current advances in clinical RNA-related technologies. Then we discussed the diagnostic and therapeutic potential (especially for immunotherapy, chemotherapy, and radiotherapy) of circRNA in CNS tumors in the context of the recent advanced research and application of RNA in clinics.

CONCLUSIONS

CircRNA are increasingly proven to participate in decveloping CNS tumors. An in-depth study of the causal mechanisms of circRNAs in CNS tomor progression will ultimately advance their implementation in the clinic and developing new strategies for preventing and treating CNS tumors.

A disintegrin and metalloproteinase 22 activates integrin β1 through its disintegrin domain to promote the progression of pituitary adenoma

BACKGROUND

Approximately 35% of pituitary adenoma (PA) display an aggressive profile, resulting in low surgical total resection rates, high recurrence rates, and worse prognosis. However, the molecular mechanism of PA invasion remains poorly understood. Although "a disintegrin and metalloproteinases" (ADAMs) are associated with the progression of many tumors, there are no reports on ADAM22 in PA.

METHODS

PA transcriptomics databases and clinical specimens were used to analyze the expression of ADAM22. PA cell lines overexpressing wild-type ADAM22, the point mutation ADAM22, the mutated ADAM22 without disintegrin domain, and knocking down ADAM22 were generated. Cell proliferation/invasion assays, flow cytometry, immunohistochemistry, immunofluorescence, co-immunoprecipitation, mass spectrometry, Reverse transcription-quantitative real-time PCR, phos-tag SDS-PAGE, and Western blot were performed for function and mechanism research. Nude mice xenograft models and rat prolactinoma orthotopic models were used to validate in vitro findings.

RESULTS

ADAM22 was significantly overexpressed in PA and could promote the proliferation, migration, and invasion of PA cells. ADAM22 interacted with integrin β1 (ITGB1) and activated FAK/PI3K and FAK/ERK signaling pathways through its disintegrin domain to promote PA progression. ADAM22 was phosphorylated by PKA and recruited 14-3-3, thereby delaying its degradation. ITGB1-targeted inhibitor (anti-itgb1) exerted antitumor effects and synergistic effects in combination with somatostatin analogs or dopamine agonists in treating PA.

CONCLUSIONS

ADAM22 was upregulated in PA and was able to promote PA proliferation, migration, and invasion by activating ITGB1 signaling. PKA may regulate the degradation of ADAM22 through post-transcriptional modification levels. ITGB1 may be a potential therapeutic target for PA.

Analysis of risk factors of pituitary neoplasms invading the sphenoidal sinus

High-resolution computed tomography (HR-CT) can more effectively discern the relationship between pituitary neoplasms (PNs) and neighboring anatomical structures. Moreover, pathological features can facilitate a more accurate determination of the growth pattern of PNs. Consequently, integrating imaging and pathological data might enhance our predictive capability regarding the growth patterns of PNs and aid in the formulation of surgical plans. We compared HR-CT images of 54 patients and 52 volunteers. Using ITK-SNAP software, we segmented and reconstructed the anatomical features of the sphenoidal sinus (SS) and calculated its volume. A comparative analysis of the invasive attributes of the 54 PNs was carried out based on clinical features and pathological data. The average volume of the SS in the volunteer group was 11.05 (8.10) mL, significantly larger than that of the PNs group at 7.45 (4.88) mL (P = .005). The postsellar type was the most common pneumatization type, and a significantly higher proportion in the PNs group exhibited a depressed saddle base (83.3%). A notable male predominance was observed for SS invasion in the PNs group (72.7%), with the Ki-67 antigen and maximum diameter significantly higher (P < .05), showing a positive correlation. The optimal cutoff points for Ki-67 antigen and the maximum diameter of PNs were 3.25% (AUC = 0.754, Sensitivity 54.5%, Specificity 90.6%) and 24.5 mm (AUC = 0.854, Sensitivity 86.4%, Specificity 78.1%), respectively. The type of pneumatization and the morphology of the sellar-floor serve as anatomical foundations for SS invasion. Factors such as the Ki-67 antigen, the maximum diameter of PNs, and high-risk sub-types constitute risk factors for PNs invasion into the SS. These insights are of significant utility for clinicians in crafting treatment strategies for PNs.

Tumor-Associated Fibroblast-Derived Exosomal circDennd1b Promotes Pituitary Adenoma Progression by Modulating the miR-145-5p/ONECUT2 Axis and Activating the MAPK Pathway

TAF participated in the progression of various cancers, including PA via the release of soluble factors. Exosomes belonged to extracellular vesicles, which were revealed as a crucial participator in intercellular communication. However, the expression pattern and effect of TAF-derived exosomes remained largely unknown in PA. In the present study, we performed in silico analysis based on public RNA-seq datasets to generate the circRNA/miRNA regulatory network. The qRT-PCR, Western blotting, RNA pull-down, and luciferase assay were performed to investigate the effect of TAF-derived exosomes. TAF-derived exosomal circDennd1b was significantly upregulated in PA and promoted the proliferation, migration, and invasion of PA cells via sponging miR-145-5p in PA cells. In addition, miR-145-5p directly regulated One Cut homeobox 2 (ONECUT2/OC2) expression and inhibited the promoting effect of ONECUT2 on PA. We further demonstrated that ONECUT2 transcriptionally increased fibroblast growth factor receptor 3 (FGFR3) expression, which further activates the mitogen-activated protein kinases (MAPK) pathway, thus promoting PA progression. Moreover, the suppression of TAFs by ABT-263 and ONECUT2 by CSRM617 inhibited the growth of PA. In conclusion, our study illustrated that TAF-derived exosomal circDennd1b affected PA progression via regulating ONECUT2 expression, which provides a potential therapeutic strategy against aggressive PA.

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

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

Targeting the Tumor Immune Microenvironment Could Become a Potential Therapeutic Modality for Aggressive Pituitary Adenoma

OBJECT

This study aimed to explore the relationship between the aggressiveness and immune cell infiltration in pituitary adenoma (PA) and to provide the basis for immuno-targeting therapies.

METHODS

One hundred and three patients with PA who underwent surgery at a single institution were retrospectively identified. The infiltration of macrophages and T-lymphocytes was quantitatively assessed.

RESULTS

The number of CD68+ macrophages was positively correlated with Knosp (p = 0.003) and MMP-9 expression grades (p = 0.00). The infiltration of CD163+ macrophages differed among Knosp (p = 0.022) and MMP-9 grades (p = 0.04). CD8+ tumor-infiltrating lymphocytes (TILs) were also positively associated with Knosp (p = 0.002) and MMP-9 grades (p = 0.01). Interestingly, MGMT expression was positively correlated with MMP-9 staining extent (p = 0.000). The quantities of CD8+ TILs (p = 0.016), CD68+ macrophages (p = 0.000), and CD163+ macrophages (p = 0.043) were negatively associated with MGMT expression levels. The number of CD68+ macrophages in the PD-L1 negative group was significantly more than that in the PD-L1 positive group (p = 0.01). The rate of PD-L1 positivity was positively correlated with the Ki-67 index (p = 0.046) and p53 expression (p = 0.029).

CONCLUSION

Targeted therapy for macrophages and CD8+ TILs could be a helpful treatment in the future for aggressive PA. Anti-PD-L1 therapy may better respond to PAs with higher Ki-67 and p53 expression and more infiltrating CD68+ macrophages. Multiple treatment modalities, especially combined with immunotherapy could become a novel therapeutic strategy for aggressive PA.

MicroRNA-149 Regulates Proliferation, Migration, and Invasion of Pituitary Adenoma Cells by Targeting ADAM12 and MMP14

OBJECTIVE

Pituitary adenomas (PAs) can adapt an aggressive phenotype by invading adjacent brain structures with rapid cellular proliferation. Previous studies demonstrated that excessive expression of metalloproteases ADAM12 and MMP-14 is instrumental for the active proliferation and invasiveness of PA cells in vitro and of tumors in vivo. However, the mechanisms regulating ADAM12 and MMP-14 expression in PAs remain unclear.

METHODS

Target gene prediction and transcriptomic profiling of invasive vs. noninvasive human PA samples were performed to identify miRNA species potentially involved in the regulation of ADAM12 and MMP14. For cellular analyses of miRNA functions, two mouse PA cell lines (AtT20 and TtT/GF) were transfected with miR-149-3p and miR-149-5p, respectively. The effects of miR-149 (3p and 5p) on expression levels of ADAM12 and MMP14 were determined by Western blotting followed by an analysis of proliferation and colony formation assays, scratch migration assays, and invasion assays.

RESULTS

A significant downregulation of miRNA-149 was observed in invasive vs. noninvasive PA (0.32 vs. 0.09, P<0.0001). In AtT-20 and TtT/GF mouse PAs cells, transfection of mimic miRNA-149 (3p and 5p) caused a significantly reduced cell proliferation and matrigel invasion, whilst the effect on cell migration was less pronounced. Both strands of miRNA-149 (3p and 5p) markedly reduced protein levels of ADAM12 and MMP-14 by at least 40% in both cell lines.

CONCLUSION

This study proved that the invasiveness of PA cells is, at least partly, regulated by miRNA-149-dependent expression of ADAM12 and MMP-14.

Clinical Biology of the Pituitary Adenoma

All endocrine glands are susceptible to neoplastic growth, yet the health consequences of these neoplasms differ between endocrine tissues. Pituitary neoplasms are highly prevalent and overwhelmingly benign, exhibiting a spectrum of diverse behaviors and impact on health. To understand the clinical biology of these common yet often innocuous neoplasms, we review pituitary physiology and adenoma epidemiology, pathophysiology, behavior, and clinical consequences. The anterior pituitary develops in response to a range of complex brain signals integrating with intrinsic ectodermal cell transcriptional events that together determine gland growth, cell type differentiation, and hormonal production, in turn maintaining optimal endocrine health. Pituitary adenomas occur in 10% of the population; however, the overwhelming majority remain harmless during life. Triggered by somatic or germline mutations, disease-causing adenomas manifest pathogenic mechanisms that disrupt intrapituitary signaling to promote benign cell proliferation associated with chromosomal instability. Cellular senescence acts as a mechanistic buffer protecting against malignant transformation, an extremely rare event. It is estimated that fewer than one-thousandth of all pituitary adenomas cause clinically significant disease. Adenomas variably and adversely affect morbidity and mortality depending on cell type, hormone secretory activity, and growth behavior. For most clinically apparent adenomas, multimodal therapy controlling hormone secretion and adenoma growth lead to improved quality of life and normalized mortality. The clinical biology of pituitary adenomas, and particularly their benign nature, stands in marked contrast to other tumors of the endocrine system, such as thyroid and neuroendocrine tumors.

Resection of the Cavernous Sinus Medial Wall Improves Remission Rate in Functioning Pituitary Tumors: Retrospective Analysis of 248 Consecutive Cases

BACKGROUND

The purpose of transsphenoidal surgery (TSS) for a functioning pituitary tumor (FPT) is to achieve endocrinological remission. The biggest challenge is aggressive tumor resection invading the cavernous sinus (CS).

OBJECTIVE

To evaluate the effects of the medial wall of CS (MWCS) resection during FPT surgery.

METHODS

Consecutive FPTs were reviewed for CS invasion (CSI) between April 2018 and December 2021. We operated on more than 250 FPTs, including 134 somatotroph tumors, 70 corticotroph tumors, 35 lactotroph tumors, and 9 thyrotroph tumors.

RESULTS

The patients were classified into 3 groups based on the relationship between the tumor and the CS: group A (no clear wall invasion), in which MWCS was not removed because of no tumorous direct contact with MWCS (N = 92) and group B (possible wall invasion), where MWCS was removed because we were not confident of MWCS invasion (N = 102). Among these 102 patients, histological tumor invasion was confirmed in 45 of 79 patients (57%) for whom histology findings were available. Tumors invading the CS clearly during surgery were classified into the "clear CS invasion" (group C: N = 55) group. The overall complete remission rate in group B was 94%, which was as high as that in group A (87%). Moreover, we clarified that microscopic invasion of MWCS could not always be predicted from Knosp grading.

CONCLUSION

MWCS invasion occurred in 57% of cases confirmed histologically where it was unclear during surgery, and its resection can improve the overall complete remission rate in FPT cases.

Complete Response of a Patient With a Mismatch Repair Deficient Aggressive Pituitary Adenoma to Immune Checkpoint Inhibitor Therapy: A Case Report

BACKGROUND AND IMPORTANCE

Aggressive pituitary adenomas (APAs) are pituitary tumors that are refractory to standard treatments and carry a poor prognosis. Current treatment guidelines are not standardized but combine surgical resection, radiation therapy, and chemotherapy. Temozolomide is the only chemotherapeutic agent with documented effectiveness and is recommended for APA in European Society of Endocrinology clinical guidelines.

CLINICAL PRESENTATION

A 57-year-old man presented with visual deterioration and bitemporal hemianopsia. MRI of the brain demonstrated a sellar mass suspected to be pituitary macroadenoma with displacement of the stalk and optic nerve impingement. The patient underwent stereotactic endoscopic transsphenoidal resection of the mass. Postoperative MRI demonstrated gross total resection. Pathology revealed a sparsely granulated corticotroph adenoma with malignant transformation. Immunohistochemistry showed loss of expression of MLH1 and PMS2 in the tumor cells. Proton therapy was recommended given an elevated Ki67 index and p53 positivity. Before radiotherapy, there was no radiographic evidence of residual tumor. Temozolomide therapy was initiated after surveillance MRI showed recurrence at 16 months postoperatively. However, MRI demonstrated marked progression after 3 cycles. Next-generation sequencing using the MSK-IMPACT platform identified somatic mutations in MLH1 Y548lfs*9 and TP53 R337C . Immunotherapy with ipilimumab/nivolumab was initiated, and MRI demonstrated no residual tumor burden 34 months postoperatively.

CONCLUSION

APA is a tumor with frequent recurrence and a short median expected length of survival. Here, we demonstrate the utility of immunotherapy in a single case report of APA, with complete resolution of recurrent APA and improved survival compared with life expectancy.

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

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

Dural Invasion as a Marker of Aggressive Pituitary Adenomas

BACKGROUND

Predictive markers of aggressive pituitary tumors have not been consistently demonstrated. Dural invasion and invasion-associated proteins, including matrix metalloproteinase-9 (MMP9) and cofilin, have been proposed to predict aggressive behavior and recurrence, but findings to date have been inconsistent.

OBJECTIVE

To assess whether microscopic dural invasion predicts aggressive pituitary adenoma behavior and whether MMP9 and cofilin expression correlates with pathological and clinical invasion markers.

METHODS

We retrospectively studied 328 consecutive pituitary mass resections by a single neurosurgeon at a single center; 254 were adenomas, and 98 had dural biopsies sent for routine pathological evaluation. Assessments included clinical features, postoperative course, and immunochemical expression of MMP9, cofilin, and phospho-cofilin. Recurrence was evaluated in those with at least 12 months of postoperative follow-up.

RESULTS

Dural invasion was evident in 48% of biopsy specimens and was associated with male sex, larger tumors, suprasellar extension and sphenoid sinus invasion, cranial nerve palsies, and hypogonadism. Recurrence rates and the expression of MMP9, cofilin, and phospho-cofilin did not differ between those with and without dural invasion. However, differential expression of phospho-cofilin was associated with growth hormone deficiency and compressive pituitary mass effects.

CONCLUSION

Dural invasion is associated with larger tumors, suprasellar and sphenoid sinus invasion, and pituitary failure but is not predictive of a more aggressive postoperative course. Routine dural biopsy is therefore of limited benefit in predicting postoperative recurrences. Cofilin expression may be an adjunctive biomarker of invasion in recurrent tumors, but MMP9 expression does not predict tumor behavior.

Classifying Pituitary Adenoma Invasiveness Based on Radiological, Surgical and Histological Features: A Retrospective Assessment of 903 Cases

Invasiveness is a major predictor of surgical outcome and long-term prognosis in patients with pituitary adenomas (PAs). We assessed PA invasiveness via radiological, surgical and histological perspectives to establish a classification scheme for predicting invasive behavior and poor prognosis. We retrospectively analyzed 903 patients who underwent transnasal-transsphenoidal surgery between January 2013 and December 2019. Radiological (hazard ratio (HR) 5.11, 95% confidence interval (CI): 3.98−6.57, p < 0.001) and surgical (HR 6.40, 95% CI: 5.09−8.06, p < 0.001) invasiveness better predicted gross-total resection (GTR) and recurrence/progression-free survival (RPFS) rates than did histological invasiveness (HR 1.44, 95% CI: 1.14−1.81, p = 0.003). Knosp grades 2 (HR 4.63, 95% CI: 2.13−10.06, p < 0.001) and 3 (HR 2.23, 95% CI: 1.39−3.59, p = 0.011) with surgical invasiveness were better predictors of prognosis than corresponding Knosp grades without surgical invasiveness. Classifications 1 and 2 were established based on radiological, surgical and histological invasiveness, and Knosp classification and surgical invasiveness, respectively. Classification 2 predicted RPFS better than Knosp classification and Classification 1. Overall, radiological and surgical invasiveness were clinically valuable as prognostic predictors. The convenience and good accuracy of Invasiveness in Classification 2 is useful for identifying invasive PAs and facilitating the development of treatment plans.

LncRNA growth arrest specific transcript 5 inhibits the growth of pituitary neuroendocrine tumors via miR-27a-5p/cylindromatosis axis

The long noncoding RNA growth arrest-specific transcript 5 (GAS5) has been reported to function as a suppressor in many cancers. However, the role and mechanism of lncRNA GAS5 in pituitary neuroendocrine tumors (PitNETs) remain unclear. Here, we found that lncRNA GAS5 and cylindromatosis (CYLD) expression was downregulated in invasive PitNET tissues and was negatively correlated with miR-27a-5p expression. LncRNA GAS5 overexpression inhibited proliferation of PitNETs cell line MMQ and GH3 cells and induced cell apoptosis, simultaneously, inhibited miR-27a-5p expression and increased CYLD expression. Moreover, miR-27a-5p mimic significantly decreased the luciferase activities of lncRNA GAS5 and CYLD luciferase reporter vector and downregulated CYLD expression, while miR-27a-5p inhibitor increased the expression of CYLD in MMQ and GH3 cells. Furthermore, RNA-immunoprecipitation assay revealed the direct binding between lncRNA GAS5 and miR-27a-5p. Additionally, miR-27a-5p mimic or silenced CYLD attenuated the effect of lncRNA GAS5 on MMQ and GH3 cell proliferation. In vivo lncRNA GAS5 overexpression inhibited GH3 cell tumor growth, while miR-27a-5p mimic or silenced CYLD attenuated the effect of lncRNA GAS5 on GH3 cell tumor growth. These results suggest that lncRNA GAS5 acts as an endogenous sponge by binding miR-27a-5p to increase the expression of its target gene CYLD, thereby inhibits PitNETs cell proliferation and tumor growth.

Muti-omics integration analysis revealed molecular network alterations in human nonfunctional pituitary neuroendocrine tumors in the framework of 3P medicine

Nonfuctional pituitary neuroendocrine tumor (NF-PitNET) is highly heterogeneous and generally considered a common intracranial tumor. A series of molecules are involved in NF-PitNET pathogenesis that alter in multiple levels of genome, transcriptome, proteome, and metabolome, and those molecules mutually interact to form dynamically associated molecular-network systems. This article reviewed signaling pathway alterations in NF-PitNET based on the analyses of the genome, transcriptome, proteome, and metabolome, and emphasized signaling pathway network alterations based on the integrative omics, including calcium signaling pathway, cGMP-PKG signaling pathway, mTOR signaling pathway, PI3K/AKT signaling pathway, MAPK (mitogen-activated protein kinase) signaling pathway, oxidative stress response, mitochondrial dysfunction, and cell cycle dysregulation, and those signaling pathway networks are important for NF-PitNET formation and progression. Especially, this review article emphasized the altered signaling pathways and their key molecules related to NF-PitNET invasiveness and aggressiveness that are challenging clinical problems. Furthermore, the currently used medication and potential therapeutic agents that target these important signaling pathway networks are also summarized. These signaling pathway network changes offer important resources for insights into molecular mechanisms, discovery of effective biomarkers, and therapeutic targets for patient stratification, predictive diagnosis, prognostic assessment, and targeted therapy of NF-PitNET.

Targeting Aggressive Pituitary Adenomas at the Molecular Level-A Review

Pituitary adenomas (PAs) are mostly benign endocrine tumors that can be treated by resection or medication. However, up to 10% of PAs show an aggressive behavior with invasion of adjacent tissue, rapid proliferation, or recurrence. Here, we provide an overview of target structures in aggressive PAs and summarize current clinical trials including, but not limited to, PAs. Mainly, drug targets in PAs are based on general features of tumor cells such as immune checkpoints, so that programmed cell death 1 (ligand 1) (PD-1/PD-L1) targeting may bear potential to cure aggressive PAs. In addition, epidermal growth factor receptor (EGFR), mammalian target of rapamycin (mTOR), vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF) and their downstream pathways are triggered in PAs, thereby modulating tumor cell proliferation, migration and/or tumor angiogenesis. Temozolomide (TMZ) can be an effective treatment of aggressive PAs. Combination of TMZ with 5-Fluorouracil (5-FU) or with radiotherapy could strengthen the therapeutic effects as compared to TMZ alone. Dopamine agonists (DAs) are the first line treatment for prolactinomas. Dopamine receptors are also expressed in other subtypes of PAs which renders DAs potentially suitable to treat other subtypes of PAs. Furthermore, targeting the invasive behavior of PAs could improve therapy. In this regard, human matrix metalloproteinase (MMP) family members and estrogens receptors (ERs) are highly expressed in aggressive PAs, and numerous studies demonstrated the role of these proteins to modulate invasiveness of PAs. This leaves a number of treatment options for aggressive PAs as reviewed here.

Aggressive pituitary neuroendocrine tumors: current practices, controversies, and perspectives, on behalf of the EANS skull base section

Aggressive pituitary neuroendocrine tumors (APT) account for 10% of pituitary tumors. Their management is a rapidly evolving field of clinical research and has led pituitary teams to shift toward a neuro-oncological-like approach. The new terminology "Pituitary neuroendocrine tumors" (PitNet) that was recently proposed to replace "pituitary adenomas" reflects this change of paradigm. In this narrative review, we aim to provide a state of the art of actual knowledge, controversies, and recommendations in the management of APT. We propose an overview of current prognostic markers, including the recent five-tiered clinicopathological classification. We further establish and discuss the following recommendations from a neurosurgical perspective: (i) surgery and multi-staged surgeries (without or with parasellar resection in symptomatic patients) should be discussed at each stage of the disease, because it may potentialize adjuvant medical therapies; (ii) temozolomide is effective in most patients, although 30% of patients are non-responders and the optimal timeline to initiate and interrupt this treatment remains questionable; (iii) some patients with selected clinicopathological profiles may benefit from an earlier local radiotherapy and/or chemotherapy; (iv) novel therapies such as VEGF-targeted therapies and anti-CTLA-4/anti-PD1 immunotherapies are promising and should be discussed as 2nd or 3rd line of treatment. Finally, whether neurosurgeons have to operate on "pituitary adenomas" or "PitNets," their role and expertise remain crucial at each stage of the disease, prompting our community to deal with evolving concepts and therapeutic resources.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

MR-Based Radiomics for Differential Diagnosis between Cystic Pituitary Adenoma and Rathke Cleft Cyst

Background

It is often tricky to differentiate cystic pituitary adenoma from Rathke cleft cyst with visual inspection because of similar MRI presentations between them. We aimed to design an MR-based radiomics model for improving differential diagnosis between them.

Methods

Conventional diagnostic MRI data (T1-,T2-, and postcontrast T1-weighted MR images) were obtained from 215 pathologically confirmed patients (105 cases with cystic pituitary adenoma and the other 110 cases with Rathke cleft cyst) and were divided into training (n = 172) and test sets (n = 43). MRI radiomics features were extracted from the imaging data, and semantic imaging features (n = 15) were visually estimated by two radiologists. Four classifiers were used to construct radiomics models through 5-fold crossvalidation after feature selection with least absolute shrinkage and selection operator. An integrated model by combining radiomics and semantic features was further constructed. The diagnostic performance was validated in the test set. Receiver operating characteristic curve was used to evaluate and compare the performance of the models at the background of diagnostic performance by radiologist.

Results

In test set, the combined radiomics and semantic model using ANN classifier obtained the best classification performance with an AUC of 0.848 (95% CI: 0.750-0.946), accuracy of 76.7% (95% CI: 64.1-89.4%), sensitivity of 73.9% (95% CI: 56.0-91.9%), and specificity of 80.0% (95% CI: 62.5-97.5%) and performed better than multiparametric model (AUC = 0.792, 95% CI: 0.674-0.910) or semantic model (AUC = 0.823, 95% CI: 0.705-0.941). The two radiologists had an accuracy of 69.8% and 74.4%, respectively, sensitivity of 69.6% and 73.9%, and specificity of 70.0% and 75.0%.

Conclusions

The MR-based radiomics model had technical feasibility and good diagnostic performance in the differential diagnosis between cystic pituitary adenoma and Rathke cleft cyst.

Morpho-Molecular Metabolic Analysis and Classification of Human Pituitary Gland and Adenoma Biopsies Based on Multimodal Optical Imaging

Pituitary adenomas count among the most common intracranial tumors. During pituitary oncogenesis structural, textural, metabolic and molecular changes occur which can be revealed with our integrated ultrahigh-resolution multimodal imaging approach including optical coherence tomography (OCT), multiphoton microscopy (MPM) and line scan Raman microspectroscopy (LSRM) on an unprecedented cellular level in a label-free manner. We investigated 5 pituitary gland and 25 adenoma biopsies, including lactotroph, null cell, gonadotroph, somatotroph and mammosomatotroph as well as corticotroph. First-level binary classification for discrimination of pituitary gland and adenomas was performed by feature extraction via radiomic analysis on OCT and MPM images and achieved an accuracy of 88%. Second-level multi-class classification was performed based on molecular analysis of the specimen via LSRM to discriminate pituitary adenomas subtypes with accuracies of up to 99%. Chemical compounds such as lipids, proteins, collagen, DNA and carotenoids and their relation could be identified as relevant biomarkers, and their spatial distribution visualized to provide deeper insight into the chemical properties of pituitary adenomas. Thereby, the aim of the current work was to assess a unique label-free and non-invasive multimodal optical imaging platform for pituitary tissue imaging and to perform a multiparametric morpho-molecular metabolic analysis and classification.

Telomerase expression in clinically non-functioning pituitary adenomas

PURPOSE

Non-functioning pituitary adenomas (NFPA) are benign tumors, however, some are agressive. We aimed to assess if human telomerase reverse transcriptase (hTERT) is present in NFPA and if it can be used as a marker of aggressiveness and proliferation.

METHODS

Consecutive patients operated for NFPA whose fresh frozen tumors were available were included. We analyzed tumor's aggressiveness (based on radiological progression) and proliferation (based on Ki-67), as well as hTERT mRNA by quantitative real-time polymerase chain reaction (RT-qPCR).

RESULTS

We included 109 samples from 86 patients followed for a median period of 60 months (5-120 months). Aggressive tumors were present in 66% cases and proliferative tumors in 47.7%. Seven (6.4%) samples expressed hTERT: 3 (42.8%) had aggressive and proliferative tumors, 2 (28.6%) only exhibited aggressiveness and the remaining 2 (28.6%) only proliferation. From the aggressive and proliferative tumors, 14% and 16%, respectively, expressed hTERT. From the non-aggressive and non-proliferative tumors, 9% and 6%, respectively, expressed hTERT.

CONCLUSION

hTERT expression is present in a minority of NFPA and does not seem to be related to aggressiveness or proliferation in NFPA.

Primary Pituitary Adenoid Cystic Carcinoma: A Rare Salivary Gland-Like Tumor in the Sella

Adenoid cystic carcinoma (ACC) is a tumor of the exocrine glands that originates primarily from the minor and major salivary glands, nasopharynx, and lacrimal glands. ACC grows slowly but is locally aggressive and prone to recurrence. It is uncommon for ACCs to develop in the pituitary gland as a primary tumor. We present a case of primary pituitary ACC extending to the sphenoid sinus resembling an invasive adenoma in a 71-year-old woman with a history of nasal epistaxis. We reviewed other reported cases of pituitary ACCs with retrospective validation of whether the tumor was primary or not. The intrasellar tumor exhibited MYB rearrangement with enlargement and destruction of the sella turcica and dural tears toward the sphenoid sinus, which would be consistent for a tumor originating from the pituitary gland. Including our case, only four intrasellar and one suprasellar ACC have been confirmed as primary tumors. All intrasellar ACCs had the characteristic of some form of invasion of neighboring structures with evidence of hyperprolactinemia. ACC could develop in the pituitary gland as a form of salivary gland-like tumor derived from the ectopic salivary gland rests. ACCs rarely arise from the pituitary gland; however, the accurate determination of primary occurrence is difficult because of the invasive nature of these tumors, and the anatomical relationship with the sphenoid sinus and the cavernous sinus. Excessive bleeding from the tumor or unexpected internal carotid artery injury should be avoided during surgery for primary and secondary pituitary ACC.

Transcriptomic analysis identifies a tumor subtype mRNA classifier for invasive non-functioning pituitary neuroendocrine tumor diagnostics

Rationale: The invasive behavior of non-functioning pituitary neuroendocrine tumors (NF-PitNEts) presents obstacles for complete surgical resection and is indicative of poor prognosis. Therefore, developing reliable diagnostic tools for identifying invasive PitNEts would be helpful in guiding surgical decisions and, in particular, the follow-up treatment.

Methods: We analyzed differential gene expression profiles between 39 non-invasive and 22 invasive NF-PitNEts by high-throughput sequencing, gene co-expression, and functional annotation. Twenty-one transcripts were further validated by Taqman-qPCR in another 143 NF-PitNEt samples. The histological expression and serum-exosomal mRNA of three candidate genes were examined by tissue microarray and droplet digital PCR.

Results: Non-invasive and invasive NF-PitNEts were clustered into distinct groups with a few outliers because of their gonadotroph, corticotroph, or null cell lineages. The gene signature with strong invasive potential was enriched in 'Pathways in cancers' and 'MAPK pathway', with significantly higher in situ INSM1 and HSPA2 protein expression in invasive NF-PitNEts. Further integration of the 20 qPCR-validated differentially expressed genes and pituitary cell lineages provided a gene-subtype panel that performed 80.00-90.24% diagnostic accuracy for the invasiveness of NF-PitNEts.

Conclusion: Our approach defined new characteristics in the core molecular network for patients at risk for invasive NF-PitNEt, representing a significant clinical advance in invasive PitNEt diagnostics.

Tumor-Associated Macrophages: New Horizons for Pituitary Adenoma Researches

Macrophages are one of the most common infiltrating immune cells and an essential component of tumor microenvironment. Macrophages and the soluble cytokines and chemokines produced play an important role in tumorigenesis, progression, invasion and metastasis in solid tumors. Despite the multiple studies in other solid tumors, there is little known about macrophages in pituitary adenomas. Recently, studies about pituitary adenoma-infiltrated macrophages have been emerging, including the immunohistochemical and immunophenotypic analysis of the pituitary adenomas and further studies into the mechanism of the crosstalk between macrophages and tumor cells in vivo and in vitro. These studies have offered us new insights into the polarization of macrophages and its role in tumorigenesis, progression and invasion of pituitary adenomas. This review describes the advances in the field of pituitary adenoma-infiltrated macrophages and the prospect of targeting macrophages as cancer therapy in pituitary adenoma.

Case Report: Temozolomide Treatment of Refractory Prolactinoma Resistant to Dopamine Agonists

Therapeutic agents for refractory prolactinomas that are resistant to dopamine agonists (DAs) are troublesome, and surgery often only removes a large part of the tumor without complete remission. Among the various second-line treatment regimens, the treatment effect of the alkylating agent temozolomide (TMZ) is only effective for approximately half of patients; however, complete remission is rare. Here we report a patient with prolactinoma who was resistant to high-dose cabergoline (CAB) treatment, demonstrating a continuous increase in both the tumor volume and the prolactin (PRL) level. Given that this case is a refractory prolactinoma, the patient underwent two transsphenoidal approach (TSA) surgeries. The pathological analysis indicated that the Ki-67 index increased significantly from 3% to 30%, and the expression levels of DRD2 and MGMT were low. Finally, TMZ treatment was recommended. A total of six cycles of TMZ standard chemotherapy shrank the tumor volume and the tumor disappeared completely. During the 6-month follow-up period, the tumor did not relapse again, and the PRL level was also normal. RNA sequencing and DNA whole genome sequencing were performed on this prolactinoma specimen, revealing 16 possible gene mutations, including a missense mutation of the PABPC1 gene. Additionally, the copy number variation analysis results showed that several chromosomes had copy number gains compared to the matched peripheral blood sample. In this case, low expression of DRD2 and high proliferation led to resistance to CAB, whereas low MGMT expression contributed to sensitivity to TMZ treatment. The results of genome sequencing still need further investigation at the molecular level to explain the tumor aggressiveness and high sensitivity to TMZ.

Cyclin A in nonfunctioning pituitary adenomas

PURPOSE

Assess cyclin A in nonfunctioning pituitary adenomas (NFPA) and compare its expression in non-invasive and non-proliferative tumors with invasive and proliferative tumors (12× higher risk of recurrence).

METHODS

Quantitative real time polymerase chain reaction to analyze cyclin A using normal pituitary gland as reference. Fold change (FC) > 1 was considered as increased. Tumor invasion was based on Knosp criteria (grades 3-4 considered invasive) and proliferation on the presence of at least two of three criteria: Ki-67 ≥ 3%; mitoses > 2/10; positive p53. Both groups were compared with Mann-Whitney test considering p value < 0.05 as statistically significant.

RESULTS

Thirty-one patients with NFPA were included. Tumors were mainly of gonadotrophic origin (74.2%), followed by corticotrophic (19.4%) and lactotrophic (3.2%) origins and null-cell adenomas (3.2%). Median tumor diameter was 3.5 cm (1.8-8.0) and Ki-67 was 3.0% (0.3-11%). Sixteen patients had tumors classified as non-invasive and non-proliferative and 15 as invasive and proliferative. Median FC was 0.31 in all tumors (0.13-1.94). Cyclin A was not related to invasion or proliferation (FC 0.41 in non-invasive and non-proliferative tumors and FC 0.30 in invasive and proliferative tumors; p = 0.968). Four (12.9%) patients had tumors that exhibited increased cyclin A [median FC of 1.04 (1.02-1.94)]-three of gonadotrophic origin and one null-cell adenoma, with two tumors classified as non-invasive and non-proliferative and two tumors classified as invasive and proliferative. Median tumor diameter in these samples was 3.4 cm (2.4-3.6) and Ki-67 was 5.1% (2-11%).

CONCLUSIONS

Cyclin A was increased in a minority of NFPA and does not seem to be related to invasion or proliferation.

[Use of chemotherapy in the treatment of aggresive pituitary adenomas]

AIM

To clarify the concept of 'aggressive pituitary adenoma' using analysis of the current concepts, as well as to determine the optimal treatment algorithm for this disease and the place of chemotherapy in this treatment. Pituitary adenomas comprise from 10 to 15% of intracranial neoplasms. Despite the fact that pituitary adenomas are benign neoplasms, in 25-55% of cases they demonstrate invasive growth, growing into the surrounding structures (sphenoid sinus, cavernous sinus, etc.). Due to the lack of a standard definition of aggressive pituitary adenomas (due to the lack of clear criteria for this disease), there are no studies in the literature reporting optimal treatment for this group of patients, except for several publications describing the use of Temozolomide as palliative therapy.

Hyperprolactinemia in Acromegaly is Related to Prolactin Secretion by Somatolactotroph Tumours

The aim of this study is to assess differences in patient characteristics, tumour characteristics and hormone levels between acromegalic patients with and without hyperprolactinemia. 44 patients of the University Hospital of Brussels, Belgium with acromegaly who were diagnosed between January 2007 and July 2018 were included in this study. Nineteen patients were classified in the hyperprolactinemia group and 25 patients were classified in the normoprolactinemia group. No significant differences between acromegalic patients with and without hyperprolactinemia were found in age at diagnosis, gender, presence of hyperprolactinemia symptoms, insulin-like growth factor 1, growth hormone and testosterone levels, tumour volume, tumour invasiveness, immunohistochemistry of growth hormone and prolactin, Ki-67 index and mitotic index. However, for a cut-off of 10% of prolactin-positive cells, there was a trend towards a higher percentage of prolactin-positive tumours in hyperprolactinemia patients (p=0.054) and higher mean prolactin level in case of positive prolactin immunostaining (p=0.007)). In our study there were no differences in characteristics between acromegaly patients with hyper- and normoprolactinemia. An association between the serum prolactin level and the positivity of prolactin immunohistochemistry of the adenoma tissue was found. The absence of a difference in tumour volume between patients with hyper- and normoprolactinemia suggests that the hyperprolactinemia is likely to be caused by the co-secretion of growth hormone and prolactin by the tumour. Finally, for the first time, the cut-off of 10% of prolactin cells was validated for the diagnosis of somatolactotroph tumours in acromegaly.

Cervical Nodal Metastatic Pituitary Carcinoma: A Case Report

Pituitary carcinomas are rare tumors with only 170 cases reported in the literature.¹ They form a very small proportion of pituitary tumors, which are commonly benign adenomas. Metastatic disease diagnosed by fine needle aspiration cytology is extremely rare and has only been reported in 6 patients,^2-5 3 of whom had cervical nodal metastases, with other sites of metastases being the liver and cervical vertebra. We report a case of cervical metastatic pituitary carcinoma diagnosed by core needle biopsy.

Anatomy of the dura mater venous sinus of Alouatta belzebul

The anatomy of the dura mater's venous sinuses is important in the veterinary clinical and surgical area, for cranial procedures and interventions of wild animals, in addition to assisting in the management of neurological diseases, which can prevent serious complications. The macroscopic anatomy of the venous sinuses of the dura mater of Alouatta belzebul was studied. Five adult specimens, males and females, were dissected and fixed in 10% formaldehyde solution. In the dura mater of the Alouatta belzebul, nine venous sinuses were observed, being them dorsal sagittal sinus, ventral sagittal sinus, transverse sinus, straight sinus, sigmoid sinus, temporal sinus, parietal sinus, basilar sinus and cavernous sinus, with morphological similarities in origin, path and destination of blood flow to the internal jugular vein, assisting in the venous drainage function of the brain in this species. These data are similar to those found in other species of non-human and human primates such as Saimiri sciureus, Sapajus libidinosus and Homo sapiens. Of the venous sinuses observed, the cavernous sinus was of considerable clinical and surgical importance in Alouatta belzebul due to its topographic arrangement next to the internal carotid artery and pituitary gland, data that corroborate Sapajus libidinosus, Macaca fascicularis, Macaca mulatta, Papio ursinus, Cercopithecus pygerithrus and Galago senegalensis. In this context, the knowledge of the macroscopic anatomy of the venous sinuses of the dura mater may contribute to the role of veterinarians in less invasive surgical procedures in non-human primates such as Alouatta belzebul and other mammals.

Malignancy course of pituitary adenoma in MEN1 syndrome: Clinical-Neuroradiological signs

Pituitary carcinomas (PCa) are extremely rare, indistinguishable from pituitary adenomas on histopathological grounds and have a poor prognosis. Most PCa start as PRL or ACTH secreting tumors in males, with relapsing invasive behaviour, refractoriness to medical and radiotherapy and increasing hormonal levels. The presence of distant metastases is still required for the diagnosis of PCa. The association with genetic endocrine diseases must be taken into account, since it adds further risk of evolution towards malignancy. Intradural spinal metastases have also been reported, so a complete craniospinal MR evaluation is recommended, when clinically indicated. We report a case of PCa, associated with MEN1 syndrome, with evidence of meningeal spread to the tentorium cerebelli, clival dura and spinal drop metastases mimicking spinal nerves schwannomas.

Biomarkers for Liquid Biopsies of Pituitary Neuroendocrine Tumors

Pituitary neuroendocrine tumors (PitNET) do not only belong to the most common intracranial neoplasms but seem to be generally more common than has been thought. Minimally invasive liquid biopsies have the potential to improve their early screening efficiency as well as monitor prognosis by facilitating the diagnostic procedures. This review aims to assess the potential of using liquid biopsies of different kinds of biomarker species that have only been obtained from solid pituitary tissues so far. Numerous molecules have been associated with the development of a PitNET, suggesting that it often develops from the cumulative effects of many smaller genetic or epigenetic changes. These minor changes eventually pile up to switch critical molecules into tumor-promoting states, which may be the key regulatory nodes representing the most potent marker substances for a diagnostic test. Drugs targeting these nodes may be superior for the therapeutic outcome and therefore the identification of such pituitary-specific cellular key nodes will help to accelerate their application in medicine. The ongoing genetic degeneration in pituitary adenomas suggests that repeated tumor profiling via liquid biopsies will be necessary for personalized and effective treatment solutions.

Identification of gene co-expression modules and hub genes associated with the invasiveness of pituitary adenoma

In pituitary adenoma (PA), invasiveness is the main cause of recurrence and poor prognosis. Thus, identifying specific biomarkers for diagnosis and effective treatment of invasive PAs is of great clinical significance. In this study, from the Gene Expression Omnibus database, we obtained and combined several microarrays of PA by the "sva" R package. Weighted gene co-expression network analysis was performed to construct a scale-free topology model and analyze the relationships between the modules and clinical traits. Our analysis results indicated that three key modules (dark turquoise, saddle brown, and steel blue) were associated with the invasiveness of PA. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis and Gene Ontology analysis were performed for the functional annotation of the key modules. In addition, the hub genes in the three modules were identified and screened by differential expression analysis between normal samples and PA samples. Three upregulated differentially expressed genes (DGAT2, PIGZ, and DHRS2) were identified. The Fisher's exact test and receiver operating characteristic curve were used to validate the capability of these genes to distinguish invasive traits, and transcription factor interaction networks were used to further explore the underlying mechanisms of the three genes. Moreover, a lower expression level of DGAT2 in invasive PA tissue than in noninvasive PA tissue was validated by quantitative reverse transcription-polymerase chain reaction. In general, this study contributes to potential molecular biomarkers of invasive PAs and provides a broader perspective for diagnosis and new therapeutic targets for the invasive PAs.

Increased E2F1 mRNA and miR-17-5p Expression Is Correlated to Invasiveness and Proliferation of Pituitary Neuroendocrine Tumours

miR-17-5p and E2F1 have been described as deregulated in cancer, but they have scarcely been studied in pituitary neuroendocrine tumours (PitNETs). This study evaluates the relationship of E2F1 and miR-17-5p with the invasiveness and proliferation of PitNETs. In this cross-sectional descriptive study, we evaluated the expression of E2F1, MYC, and miR-17-5p by quantitative real time PCR analysis in 60 PitNETs: 29 gonadotroph (GT), 15 functioning somatotroph (ST), and 16 corticotroph (CT) tumours, of which 8 were silent (sCT). The clinical data were collected from the Spanish Molecular Register of Pituitary Adenomas (REMAH) database. We defined invasiveness according to the Knosp classification and proliferation according to a molecular expression of Ki-67 ≥ 2.59. E2F1 was more expressed in invasive than in non-invasive tumours in the whole series (p = 0.004) and in STs (p = 0.01). In addition, it was overexpressed in the silent subtypes (GTs and sCTs; all macroadenomas) and normoexpressed in the functioning ones (fCTs and STs; some microadenomas). miR-17-5p was more expressed in proliferative than in non-proliferative tumours (p = 0.041) in the whole series but not by subtypes. Conclusions: Our study suggests that in PitNETs, E2F1 could be a good biomarker of invasiveness, and miR-17-5p of proliferation, helping the clinical management of these tumours.

Malignant Prolactinoma With Liver Metastases Masquerading as Metastatic Gastrointestinal Stromal Tumor: A Case Report and Literature Review

Pituitary carcinomas are rare diseases defined as pituitary tumors with metastases. In this report, we describe a case of malignant prolactinoma with liver metastases masquerading as metastatic gastrointestinal stromal tumor (GIST). A 54-years-old woman received dopamine agonists for macroprolactinoma for 2 years, followed by transsphenoidal surgery due to a poor response to medical therapy. Despite the continuation of dopamine agonist after surgery, serum prolactin level progressively increased to above 8,000 ng/ml in 5 years. There was no evidence of disease recurrence on sella magnetic resonance imaging (MRI). She stopped medical therapy. Meanwhile, she was diagnosed with GIST accompanied by liver and peritoneal metastases. After a 2-months treatment with imatinib, she suddenly presented with headache and visual impairment. Sella MRI showed a 3.3-cm sized pituitary mass, and serum prolactin levels were still high. For the recurred mass, she underwent a second surgery followed by radiation therapy. During the imatinib treatment for GIST, main mass and peritoneal metastases were dramatically decreased, but liver metastases were markedly aggravated. Liver masses were eventually confirmed as metastases from prolactin-producing pituitary carcinoma and not from GIST by percutaneous biopsy. Unfortunately, she died 6 months after the second surgery due to acute renal failure and sepsis. This case suggests that highly sustained serum prolactin levels during the dopamine agonist may indicate prolactin-producing pituitary carcinomas with hidden metastases.

Pituitary Adenomas and Invasiveness from Anatomo-Surgical, Radiological, and Histological Perspectives: A Systematic Literature Review

Invasiveness in pituitary adenomas has been defined and investigated from multiple perspectives, with varying results when its predictive value is considered. A systematic literature review, following PRISMA guidelines, was performed, searching PubMed and Scopus databases with terms that included molecular markers, histological, radiological, anatomical and surgical data on invasiveness of pituitary adenomas. The results showed that differing views are still present for anatomical aspects of the sellar region that are relevant to the concept of invasiveness; radiological and histological diagnoses are still limited, but might improve in the future, especially if they are related to surgical findings, which have become more accurate thanks to the introduction of the endoscope. The aim is to achieve a correct distinction between truly invasive pituitary adenomas from those that, in contrast, present with extension in the parasellar area through natural pathways. At present, diagnosis of invasiveness should be based on a comprehensive analysis of radiological, intra-operative and histological findings.

Line Scan Raman Microspectroscopy for Label-Free Diagnosis of Human Pituitary Biopsies

Pituitary adenomas are neoplasia of the anterior pituitary gland and can be subdivided into hormone-producing tumors (lactotroph, corticotroph, gonadotroph, somatotroph, thyreotroph or plurihormonal) and hormone-inactive tumors (silent or null cell adenomas) based on their hormonal status. We therefore developed a line scan Raman microspectroscopy (LSRM) system to detect, discriminate and hyperspectrally visualize pituitary gland from pituitary adenomas based on molecular differences. By applying principal component analysis followed by a k-nearest neighbor algorithm, specific hormone states were identified and a clear discrimination between pituitary gland and various adenoma subtypes was achieved. The classifier yielded an accuracy of 95% for gland tissue and 84–99% for adenoma subtypes. With an overall accuracy of 92%, our LSRM system has proven its potential to differentiate pituitary gland from pituitary adenomas. LSRM images based on the presence of specific Raman bands were created, and such images provided additional insight into the spatial distribution of particular molecular compounds. Pathological states could be molecularly differentiated and characterized with texture analysis evaluating Grey Level Cooccurrence Matrices for each LSRM image, as well as correlation coefficients between LSRM images.

LncRNA XIST depletion prevents cancer progression in invasive pituitary neuroendocrine tumor by inhibiting bFGF via upregulation of microRNA-424-5p

Background

Long noncoding RNAs (lncRNAs) are vital mediators in human cancers including pituitary neuroendocrine tumor (PitNET) and could function as competing endogenous RNAs (ceRNAs) of microRNAs (miRNAs). The main objective of this study is to identify effect of lncRNA X-inactive specific transcript (XIST) and microRNA-424-5p (miR-424-5p) on PitNET.

Methods

Microarray analysis was employed to identify the PitNET-related differentially expressed lncRNAs. PitNET tissues, including both invasive and non-invasive subtypes in parallel with normal pituitary tissues were collected for the determination of the expression of XIST, miR-424-5p and basic fibroblast growth factor (bFGF) and the interaction among them. Subsequently, the expression of XIST, miR-424-5p and bFGF in PitNET cells was altered to elucidate their biological significance in the aspects of proliferation, migration, invasion, and the apoptosis.

Results

Both XIST and bFGF exhibited high expression, but miR-424-5p had a low expression in invasive PitNET tissues as compared to non-invasive PitNET normal pituitary tissues. Additionally, XIST competitively bound to miR-424-5p to elevate the expression of bFGF. Furthermore, depleted XIST or bFGF, or elevated miR-424-5p was revealed to suppress the proliferation, migration, invasion, and promote cell cycle arrest and apoptosis of invasive PitNET cells. miR-424-5p repressed the proliferation, migration, invasion of invasive PitNET cells by targeting bFGF.

Conclusion

In conclusion, the fundamental findings of the present study suggested that the functional suppression of XIST downregulated bFGF to inhibit the development of PitNET by increasing miR-424-5p expression, proposing XIST as a novel therapeutic target for PitNET.

Endothelial cell-specific molecule-1 as an invasiveness marker for pituitary null cell adenoma

BACKGROUND

Endothelial cell-specific molecule-1 (ESM-1) is a biomarker associated with tumor progression in pituitary adenoma. We specifically focused on one type of pituitary adenoma, namely null cell adenoma (NCA) and evaluated the relationship between invasion and ESM-1 expression in both vascular endothelial and adenoma tissues.

METHODS

Tissue samples from 94 patients with pituitary NCA were obtained through microscopic transsphenoidal resection. Tumor size and invasion were determined through preoperative magnetic resonance imaging. Immunohistochemical staining was performed to detect ESM-1 expression. ESM-1 index of ≥3 was defined as high expression.

RESULTS

Signs of invasion were observed in 46 (47.9%) of the 94 patients. Significant differences were observed in the invasion state and maximum tumor diameter between high and low expression of ESM-1 in vascular endothelial tissues (both P < 0.05). Significant positive associations were noted between ESM-1 expression in vascular endothelial tissues and tumor invasion (P = 0.002) and tumor size (P = 0.020). However, only tumor size was associated with ESM-1 expression in adenoma tissues (P = 0.016).

CONCLUSION

In NCA, a significant positive association between tumor invasion and ESM-1 expression was observed only in vascular endothelial tissues, suggesting that tumor progression occurs mainly through ESM-1-associated mechanism.

Diagnosis of Invasive Nonfunctional Pituitary Adenomas by Serum Extracellular Vesicles

The invasiveness evaluation of nonfunctional pituitary adenoma (NFPAs) is crucial for the prediction of the malignant potential and for making surgical plans of NFPAs. Current invasiveness evaluation of NFPAs is based on neuroimaging, which can hardly predict the invasive potential and dynamically monitor disease progress. Here we used microbead-assisted flow cytometry to detect and analyze the serum extracellular vesicles (EVs) from 30 NFPAs patients (15 invasive and 15 noninvasive). Lower expressions of folate receptor 1 (FOLR1) and epithelial cell adhesion molecule (EpCAM) were found in serum EVs from the invasive NFPAs patients compared to the noninvasive ones [area under the curve (AUC) of 0.94 for FOLR1 and 0.88 for EpCAM]. Meanwhile, increased mRNA expression of vimentin and N-cadherin, two mesenchymal markers, was found in serum EVs from the invasive NFPAs patients compared to the noninvasive ones. Consistent results were observed in the tumor tissue that invasive NFPAs have lower expression of the epithelial markers while higher expression of the mesenchymal markers. These results suggested the possible role of epithelial-mesenchymal transition (EMT) in the invasiveness of NFPAs. Pituitary tumor transforming gene 1 (PTTG1) mRNA in serum EVs was also found to be an indicator for invasive NFPAs and is related with EMT. These results provide a method for the blood-based diagnosis and invasiveness evaluation of NFPAs and would be beneficial to the diagnosis, prognosis prediction, and surgical risk evaluation of NFPAs.

The medial wall of the cavernous sinus. Part 2: Selective medial wall resection in 50 pituitary adenoma patients

OBJECTIVE

Pituitary adenomas often invade the medial wall of the cavernous sinus (CS), but this structure is generally not surgically removed because of the risk of vascular and cranial nerve injury. The purpose of this study was to report the surgical outcomes in a large series of cases of invasive pituitary adenoma in which the medial wall of the CS was selectively removed following an anatomically based, stepwise surgical technique.

METHODS

The authors' institutional database was reviewed to identify cases of pituitary adenoma with isolated invasion of the medial wall, based on an intraoperative evaluation, in which patients underwent an endoscopic endonasal approach with selective resection of the medial wall of the CS. Cases with CS invasion beyond the medial wall were excluded. Patient complications, resection, and remission rates were assessed.

RESULTS

Fifty patients were eligible for this study, 15 (30%) with nonfunctional adenomas and 35 (70%) with functional adenomas, including 16 growth hormone-, 10 prolactin-, and 9 adrenocorticotropic hormone (ACTH)-secreting tumors. The average tumor size was 2.3 cm for nonfunctional and 1.3 cm for functional adenomas. Radiographically, 11 cases (22%) were Knosp grade 1, 23 (46%) Knosp grade 2, and 16 (32%) Knosp grade 3. Complete tumor resection, based on intraoperative impression and postoperative MRI, was achieved in all cases. The mean follow-up was 30 months (range 4-64 months) for patients with functional adenomas and 16 months (range 4-30 months) for those with nonfunctional adenomas. At last follow-up, complete biochemical remission (using current criteria) without adjuvant treatment was seen in 34 cases (97%) of functional adenoma. No imaging recurrences were seen in patients who had nonfunctional adenomas. A total of 57 medial walls were removed in 50 patients. Medial wall invasion was histologically confirmed in 93% of nonfunctional adenomas and 83% of functional adenomas. There were no deaths or internal carotid artery injuries, and the average blood loss was 378 ml. Four patients (8%) developed a new, transient cranial nerve palsy, and 2 of these patients required reoperation for blood clot evacuation and fat graft removal. There were no permanent cranial nerve palsies.

CONCLUSIONS

The medial wall of the CS can be removed safely and effectively, with minimal morbidity and excellent resection and remission rates. Further follow-up is needed to determine the long-term results of this anatomically based technique, which should only be performed by very experienced endonasal skull base teams.

Differential Expression of HMGA1 and HMGA2 in pituitary neuroendocrine tumors

Defining biomarkers for invasive pituitary neuroendocrine tumors (PitNETs) is highly desirable. The high mobility group A (HMGA) proteins are among the most widely expressed cancer-associated proteins. Indeed, their overexpression is a frequent feature of human malignancies, including PitNETs. We show that nonfunctioning PitNETs (NF-PitNETs) express significantly higher levels of HMGA1 than somatotropinomas (GHs) and corticotropinomas (ACTHs). Furthermore, HMGA2 expression was detected only in NF-PitNETs and was significantly higher in larger tumors than in smaller tumors. HMGA expression analysis generally focuses on nuclear staining. Here, cytoplasmic HMGA staining was also found. PitNETs displayed strong nuclear HMGA1 and strong cytoplasmic HMGA2 immunoreactivity. Interestingly, the HMGA1 and HMGA2 nuclear expression levels were significantly higher in invasive adenomas than in noninvasive adenomas. The highest levels of nuclear HMGA2 were found in GHs. In conclusion, we show that overexpression of nuclear HMGA proteins could be a potential biomarker of invasive PitNETs, particularly HMGA2 for GHs. HMGA2 might be a reliable biomarker for NF-PitNETs.

A Population-Level Analysis of Pituitary Carcinoma from the National Cancer Database

Objectives  Pituitary carcinoma is a rare entity with fewer than 200 total cases reported in the English literature. Analysis of the population-level data from the National Cancer Database (NCDB) affords the opportunity to study this poorly understood tumor type. Methods  The NCDB was queried for site, histology, and metastasis codes corresponding to pituitary carcinoma. Statistical analyses were performed to determine factors associated with overall survival (OS). Results  A total of 92 patients with pituitary carcinoma met inclusion criteria. The 1 and 5 years of OS for all patients was 93.3% (95% confidence interval [CI]: 88.2-98.6%) and 80.0% (95% CI: 71.6-89.4%), respectively. Patients with invasive primary tumor behavior had 1 and 5 years of OS of 69.2% (95% CI: 48.2-99.5%) and 52.7% (95% CI: 31.2-89.2%), respectively. Multivariate analysis demonstrated that compared with benign primary behavior, invasive behavior had increased all-cause mortality (hazard ratio [HR], 1,296, 95% CI: 15.1- > 2,000). Surgery without adjuvant radiation or chemotherapy was the most common therapy (48.9%), followed by no treatment (40.2%). Compared with surgery alone, no treatment had worse OS (HR, 11.83, 95% CI: 1.41-99.56). Increasing age and female sex were both associated with increased mortality. Conclusions  The most common treatment for pituitary carcinoma is surgery alone followed by no surgery. Surgery alone has significantly better OS compared with no treatment. The efficacy of radiation, chemotherapy, and neurohormonal treatments needs to be examined with prospective studies.