Sporadic Pituitary Adenomas Research Articles

EPCO-35. GENOMIC CHARACTERIZATION OF GROWTH HORMONE SECRETING PITUITARY ADENOMAS

Abstract BACKGROUND Pituitary adenomas (PAs) are the second most common brain tumors in adults with prevalence ranging from 80 to 100 per 100,000 individuals. Of these, 9% to 14% are growth hormone (GH)-secreting PAs. While recurrent somatic GNAS mutations are identified in approximately half of sporadic GH-secreting PAs, the remaining cases are not well-characterized. This study aims to expand the genomic profile of GH-secreting PAs and explore correlations between molecular and clinical features. METHODS Whole exome sequencing (WES) was performed on 19 tumors with matching blood samples from consenting patients, achieving mean coverages of 262.74X for tumor samples and 112.43X for blood samples. Somatic variants, including single nucleotide variants (SNVs), short insertions/deletions (INDELs), and copy number variations (CNVs), were identified, and analyzed using protocols established by our institution. Genomic instability was assessed by calculating the percentage of the genome displaying loss-of-heterozygosity (LOH). Clinical data were collected and analyzed to establish genomic correlations. RESULTS The cohort comprised 19 GH-secreting PAs, with a mean age of 46 years at surgery, and was predominantly female (78.9%). The cohort was enriched for macroadenomas, with a mean tumor size of 18.4 mm. WES revealed a mean somatic mutation count of 20.4 (range 7-79), with 47% of cases harboring recurrent GNAS mutations. The mean alteration by LOH across the cohort was 11.13% (range: 0-44.80%) and did not show a statistically significant difference between cases with GNAS mutations and GNAS-wildtype cases (7.71% vs. 14.21%, respectively). Chromosomes 3, 8, 16, 22q were frequently affected by CNV/LOH events. CONCLUSION Comprehensive genomic characterization, including assessment of genomic instability through CNV/LOH analysis, is critical for better understanding the pathogenesis of GH-secreting PAs. This study underscores the importance of detailed genomic profiling in larger cohorts for improving the diagnosis and management of these tumors.

Long term outcomes of pituitary adenomas in Multiple Endocrine Neoplasia type 1: a nationwide study.

Historically, Multiple Endocrine Neoplasia type 1 (MEN1)-related pituitary adenomas (PAs) were considered more aggressive and treatment-resistant than sporadic PAs. However, recent studies suggest similarities in their behavior. This study aimed to evaluate the long-term outcomes of MEN1 PAs and identify predictive factors. Nationwide multicenter retrospective cohort study of MEN1-related PAs with a minimum 1-year follow-up, collecting patient demographics, germline MEN1 pathogenic variants (PV), PA size, secretory profile, radiological characteristics, treatments, and outcomes. We analyzed 84 PAs, 69%in females and 31% in males (P<0.001), diagnosed at a mean age of 35.2±14.9 years, mostly through screening (60.7%). Median follow-up was 9 years (IQR:4-16). Prolactin-secreting PAs (PRLomas) (53.5%) and microadenomas (65.5%) were most common. Dopamine agonist treatment was first line for 16 macroPRLomas and 25 microPRLomas, 60.9% of them achieved PRL normalization. There was no significant association observed with tumor size, sex, treatment duration or MEN1 PV. The risk of progression from micro-PA to invasive macro-PA was 7.2% (4/55), after 8 years (IQR:4-13), all of them were microPRLomas. Kaplan-Meier estimation curve showed significantly higher progression probability in microPRLomas than in other microadenomas subtypes (P=0.017) or microNFPAs (P=0.032). No differences were found between sex, age, or germline MEN1 PV. MEN1-related micro-PAs have a low risk of progressing to invasive macro-PAs, regardless of sex, age at diagnosis, or MEN1 germline PV. The risk is higher for microPRLomas over the long term. Therefore, long-term surveillance with reduced frequency, rather than intensive short-term monitoring, may be appropriate for patients with MEN1-related PAs.

Germline Variants in Sporadic Pituitary Adenomas.

Data on germline genetics of pituitary adenomas (PAs) using whole-exome sequencing (WES) are limited. This study investigated the germline genetic variants in patients with PAs using WES. We studied 134 consecutive functioning (80.6%) and nonfunctioning (19.4%) PAs in 61 female (45.5%) and 73 male patients (54.5%). Their median age was 34 years (range, 11-85 years) and 31 patients had microadenomas (23.0%) and 103 macroadenomas (77%). None of these patients had family history of PA or a known PA-associated syndrome. Peripheral blood DNA was isolated and whole-exome sequenced. We used American College of Medical Genetics and Genomics (ACMG) criteria and a number of in silico analysis tools to characterize genetic variant pathogenicity levels and focused on previously reported PA-associated genes. We identified 35 variants of unknown significance (VUS) in 17 PA-associated genes occurring in 40 patients (29.8%). Although designated VUS by the strict ACGM criteria, they are predicted to be pathogenic by in silico analyses and their extremely low frequencies in 1000 genome, gnomAD, and the Saudi Genome Project databases. Further analysis of these variants by the Alpha Missense analysis tool yielded 8 likely pathogenic variants in 9 patients in the following genes: AIP:c.767C>T (p.S256F), CDH23:c.906G>C (p.E302D), CDH23:c.1096G>A (p.A366T), DICER1:c.620C>T (p.A207V), MLH1:c.955G>A (p.E319K), MSH2:c.148G>A (p.A50T), SDHA:c.869T>C (p.L290P) and USP48 (2 patients): c.2233G>A (p.V745M). This study suggests that about 6.7% of patients with apparently sporadic PAs carry likely pathogenic variants in PA-associated genes. These findings need further studies to confirm them.

SAT604 An Extensively Invasive Giant Prolactinoma Associated With CDH23 Mutation

Abstract Disclosure: B. Alghamdi: None. L.A. Alobaid: None. M. Alswailem: None. E.O. Othman: None. M. Dababo: None. O. Alsagheir: None. A.S. Alzahrani: None. Pituitary adenomas (PA), renamed recently pituitary neuroendocrine neoplasms, are common and prolactinomas are the most common subtype of these tumors. The vast majority of PA are sporadic but they can also be due to germline (∼ 5%), mosaic (&amp;lt;1%) or somatic mutations (∼40%). PA with germline mutations might be part of a syndrome such as MEN1 or apparently sporadic, either due to de novo mutations or because of low penetrance of the underlying gene (e.g. AIP). Among the several genes that have been identified, CDH23 was reported to be associated with familial PA in a single study that included 12 families with PA (33% of them had CDH23 variants) and 125 sporadic PA (15 (12%) of them harbored CDH23 variants) compared to only 0.8% of 260 healthy controls. In this report, we describe a middle-aged woman who was incidentally found to have a huge macroprolactinoma with extensive invasion. Genetic testing revealed a novel germline CDH23 variant. Case report: A 53-year-old woman who with hypertension, diabetes and chronic renal insufficiency diagnosed 4 years before. She accidentally fell down on the back of her head. A CT and subsequent MRI scans of the head showed a huge mass extensively involving the Sella, suprasellar space, the cavernous sinuses and middle fossae. This mass extends inferiorly to the sphenoid and parasellar sinuses, nasopharynx, and appears at the nostrils. The patient reported chronic headaches, snoring and congested nose, and worsening hearing and vision over the last 4 years. She denied history of galactorrhea and her periods ceased 8 years before. She never got married and has no children. Her family history is negative for any pituitary or other tumors. The mass was initially thought to be a nasopharyngeal cancer. However, a bedside biopsy from the protruding mass in the right nostril revealed a pituitary tissue strongly positive for prolactin and weakly positive for growth hormone (GH). An undiluted serum prolactin level was 47 ug/l (3.4-24). After several dilutions for the hook effect, the level was 578,000 ug/l (3.4-24). IGF-1 253 ng/ml (93-245), random GH 4.7 ng/ml, TSH 1.9 mU/l (0.4-4.2), FT4 11.4 pmol/l (12-22), AM cortisol 235 nmol/l (159-620), ACTH 27.6 (5-60). Whole exome sequencing followed by Sanger sequencing revealed a novel variant in CDH23 (c.2621C&amp;gt;A, p.Ala874Asp). Several in silico analyses suggest that this variant is pathogenic and it is assigned variant of unknown significance (VUS) according to American College of Medical Genetics (ACMG) classification. It is not reported in EXAC and 1000G databases. All other known PA-associated genes and cancer-associated genes revealed no pathogenic variants. Conclusion: We report a massive prolactinoma, likely due to a novel CDH23 variant. This is the second report on the likely pathogenic role of this gene in PA. In the case reported here, it is associated with a huge and highly invasive pituitary macroadenoma. Presentation: Saturday, June 17, 2023

Germline loss-of-function PAM variants are enriched in subjects with pituitary hypersecretion.

Pituitary adenomas (PAs) are common, usually benign tumors of the anterior pituitary gland which, for the most part, have no known genetic cause. PAs are associated with major clinical effects due to hormonal dysregulation and tumoral impingement on vital brain structures. PAM encodes a multifunctional protein responsible for the essential C-terminal amidation of secreted peptides. Following the identification of a loss-of-function variant (p.Arg703Gln) in the peptidylglycine a-amidating monooxygenase (PAM) gene in a family with pituitary gigantism, we investigated 299 individuals with sporadic PAs and 17 familial isolated PA kindreds for PAM variants. Genetic screening was performed by germline and tumor sequencing and germline copy number variation (CNV) analysis. In germline DNA, we detected seven heterozygous, likely pathogenic missense, truncating, and regulatory SNVs. These SNVs were found in sporadic subjects with growth hormone excess (p.Gly552Arg and p.Phe759Ser), pediatric Cushing disease (c.-133T>C and p.His778fs), or different types of PAs (c.-361G>A, p.Ser539Trp, and p.Asp563Gly). The SNVs were functionally tested in vitro for protein expression and trafficking by Western blotting, splicing by minigene assays, and amidation activity in cell lysates and serum samples. These analyses confirmed a deleterious effect on protein expression and/or function. By interrogating 200,000 exomes from the UK Biobank, we confirmed a significant association of the PAM gene and rare PAM SNVs with diagnoses linked to pituitary gland hyperfunction. The identification of PAM as a candidate gene associated with pituitary hypersecretion opens the possibility of developing novel therapeutics based on altering PAM function.

Low frequency of AIP mutations in patients with young-onset sporadic pituitary macroadenomas

PurposeMutations in the aryl hydrocarbon receptor interacting protein (AIP) gene cause familial isolated pituitary adenomas (FIPA). AIP mutations have also been found in patients with apparently sporadic pituitary adenomas, particularly in young patients with large adenomas. The aim of this study was to determine the frequency of AIP germline mutations in patients with young-onset sporadic pituitary macroadenomas.MethodsThe AIP gene was sequenced in 218 Portuguese patients with sporadic pituitary macroadenomas diagnosed before the age of 40 years.ResultsHeterozygous rare sequence variants in AIP were identified in 18 (8.3%) patients. However, only four (1.8%) patients had pathogenic or likely pathogenic variants. These consisted of two already known mutations (p.Arg81* and p.Leu115Trpfs*41) and two novel mutations (p.Glu246*, p.Ser53Thrfs*36). All four patients had GH-secreting adenomas diagnosed between the ages of 14 and 25 years. The frequency of AIP pathogenic or likely pathogenic variants in patients under the age of 30 and 18 years was 3.4% and 5.0%, respectively.ConclusionThe frequency of AIP mutations in this cohort was lower than in other studies. Previous reports may have overestimated the contribution of AIP mutations due to the inclusion of genetic variants of uncertain significance. The identification of novel AIP mutations expands the known spectrum of genetic causes of pituitary adenomas and may help understand the role of AIP mutations in the molecular mechanisms underlying pituitary tumorigenesis.

A Common Variant in the CDK8 Gene Is Associated with Sporadic Pituitary Adenomas in the Portuguese Population: A Case-Control Study.

The majority of pituitary adenomas occur in a sporadic context, and in the absence of known genetic predisposition. Three common variants at the NEBL (rs2359536), PCDH15 (rs10763170) and CDK8 (rs17083838) loci were previously associated with sporadic pituitary adenomas in the Han Chinese population, but these findings have not yet been replicated in any other population. The aim of this case-control study was to assess if these variants are associated with susceptibility to sporadic pituitary adenomas in the Portuguese population. Genotype and allele frequencies were determined in 570 cases and in 546 controls. The CDK8 rs17083838 minor allele (A allele) was significantly associated with sporadic pituitary adenomas, under an additive (odds ratio (OR) 1.73, 95% confidence interval (CI) 1.19–2.50, p = 0.004) and dominant (OR 1.82, 95% CI 1.24–2.68, p = 0.002) inheritance model. The NEBL rs2359536 and PCDH15 rs10763170 variants were not associated with the overall risk for the disease, although a borderline significant association was observed between the PCDH15 rs10763170 minor allele (T allele) and somatotrophinomas (dominant model, OR 1.55, 95% CI 1.02–2.35, p = 0.035). These findings suggest that the CDK8 rs17083838 variant, and possibly the PCDH15 rs10763170 variant, may increase susceptibility to sporadic pituitary adenomas in the Portuguese population.

Pituitary adenomas evade apoptosis via noxa deregulation in Cushing's disease.

SUMMARYSporadic pituitary adenomas occur in over 10% of the population. Hormone-secreting adenomas, including those causing Cushing’s disease (CD), cause severe morbidity and early mortality. Mechanistic studies of CD are hindered by a lack of in vitro models and control normal human pituitary glands. Here, we surgically annotate adenomas and adjacent normal glands in 25 of 34 patients. Using single-cell RNA sequencing (RNA-seq) analysis of 27594 cells, we identify CD adenoma transcriptomic signatures compared with adjacent normal cells, with validation by bulk RNA-seq, DNA methylation, qRT-PCR, and immunohistochemistry. CD adenoma cells include a subpopulation of proliferating, terminally differentiated corticotrophs. In CD adenomas, we find recurrent promoter hypomethylation and transcriptional upregulation of PMAIP1 (encoding pro-apoptotic BH3-only bcl-2 protein noxa) but paradoxical noxa downregulation. Using primary CD adenoma cell cultures and a corticotroph-enriched mouse cell line, we find that selective proteasomal inhibition with bortezomib stabilizes noxa and induces apoptosis, indicating its utility as an anti-tumor agent.

Pituitary adenoma-Gonadotroph type in a 47 years old female patient: A case report

Pituitary adenomas are tumors of the anterior pituitary. Most pituitary tumors are slow-growing and benign. They are classified based on size or cell of origin. Pituitary adenoma can be classified as microadenoma, macroadenoma, and giant tumors based on size.Pituitary adenomas are mostly found incidentally on imaging modalities obtained for other reasons. Mutations in known Oncogenes have little role in the pathogenesis of most sporadic pituitary adenomas. Case presentation : A 47 years old female patient presented with complain of diminished vision , severe headache and dizziness since 1 months.MRI was advised which showed an ill-defined low signal intensity lesion of approximate 3.4x3.2x3 cm noted in clivus, bilateral spenoid sinus and sella region. Histologically, near-signature appearance is that of elongated cells surrounding blood vessels in a pseudorosette-like ependymoma-mimicking pattern. cells with small round nuclei and there is no significant mitotic activity. Conclusion : Pitutary adenoma-gonadotroph type is benign and can cause symptoms from mass effect or by effecting the level of the hormones. Differetial diagnosis includes ependymoma, Pitutary blastoma, Pitutary nodular hyperplasia, dermoid cyst, low grade astrocytoma, meningioma, rathke cleft cyst.

Molecular genetic testing in the management of pituitary disease.

Most pituitary tumours occur sporadically without a genetically identifiable germline abnormality, a small but increasing proportion present with a genetic defect that predisposes to pituitary tumour development, either isolated (e.g.,aryl hydrocarbon receptor-interacting protein, AIP) or as part of a tumour-predisposing syndrome (e.g.,multiple endocrine neoplasia (MEN) type 1, Carney complex, McCune-Albright syndrome or pituitary tumour and paraganglioma association). Genetic alterations in sporadic pituitary adenomas may include somatic mutations (e.g., GNAS, USP8). In this review, we take a practical approach: which genetic syndromes should be considered in case of different presentation, such as tumour type, family history, age of onset and additional clinical features of the patient. Review of the recent literature in the field of genetics of pituitary tumours. Genetic testing in the management of pituitary disease is recommended in a significant minority of the cases. Understanding the genetic basis of the disease helps to identify patients and at-risk family members, facilitates early diagnosis and therefore better long-term outcome and opens up new pathways leading to tumorigenesis. We provide a concise overview of the genetics of pituitary tumours and discuss the current challenges and implications of these genetic findings in clinical practice.

508 Syngeneic Pair-wise Transcriptomic/Epigenomic Analysis of Sporadic Cushing’s Adenomas and Adjacent Gland Reveals Novel Tumorigenic Pathways

INTRODUCTION: Sporadic pituitary adenomas are found in more than 10% of the general population and are mutationally bland. The normal human pituitary transcriptome is unknown, precluding syngeneic studies on Cushing's disease (CD) pathogenesis. METHODS: We surgically annotated adenomas and adjacent normal glands and performed single cell RNAseq (scRNAseq; 10X Genomics Chromium 3’) on 28,724 cells from 6 patients (3 CD and 3 non-CD). We performed bulk RNAseq (Illumina Nextseq) in 7 patients (5 CD and 2 non-CD) and DNA methylation analysis (Illumina Infinium MethylEPIC 850k) in 6 patients (3 CD and 3 non-CD). Transcriptomic/epigenomic data were analyzed using R packages and custom Python pipelines for pairwise differential expression analyses. RESULTS: We mapped the post-natal human pituitary gland at single cell resolution and identified canonical resident pituitary cell classes. Corticotrophs were abundant within CD adenomas but rare in the surrounding normal gland, with downregulated POMC expression consistent with repression in the hypercortisolemic state. CD corticotrophs overexpressed signature genes PCSK1, PPP1R17, EGLN, RSPO3 and PMAIP1 compared to surrounding tissues. This gene signature was specific for core adenomas and correlated with anatomic demarcation at the time of surgery. We confirmed overexpression of PCSK1, PPP1R17, RSPO3 and PMAIP1 by independent RNAseq. We identified hypomethylation at the promoters of PMAIP1, PPP1R17 and RSPO3 but not PCSK1 or EGLN1 in CD adenomas. CONCLUSION: We mapped the transcriptome of the adult human pituitary gland, identified novel signature genes for CD and highlighted DNA methylation as an epigenetic mechanism of transcriptional activation in a number of Cushing’s adenoma signature genes. We provide novel, targetable mechanistic pathways for therapeutic intervention in Cushing’s disease.

The Clinical Features and Molecular Mechanism of Pituitary Adenoma Associated With Vestibular Schwannoma.

To explore the clinical features and mechanism of pituitary adenoma associated with vestibular schwannoma (PAVS). The authors retrospectively reviewed pituitary adenoma patients in Beijing Tiantan Hospital from January 1, 2008 to December 31, 2016. A total of two pituitary adenoma samples, 1 vestibular schwannoma sample and one paired pituitary adenoma/blood sample were subjected next-generation sequencing and sanger sequence. A total of 5675 pituitary adenoma patients from January 1, 2008 to December 31, 2016, were retrospectively analyzed; of these, 4 (7%) patients met the criteria of PAVS. Clinical variable analyses revealed significant correlations between PAVS and older age when compared with sporadic pituitary adenoma (SPA) or sporadic vestibular schwannoma (SVS). The authors found that there were 2 germline mutations of XKR3 in 2/4 PAVS patients. Therefore, the authors speculated that XKR3 might be a genetic predisposition factor. The result also showed that there was no NF2 mutation and NF2-related symptom in the 4 PAVS samples. PAVS had a significant correlation with older age when compared with SPA and SVS. XKR3 may be a genetic predisposition factor for PAVS, it represents a therapeutic target for PAVS in the future.

Clinical and genetic characteristics in patients under 30 years with sporadic pituitary adenomas.

Pituitary adenomas (PA) are rare in young patients, and additional studies are needed to fully understand their pathogenesis in this population. We describe the clinical and genetic characteristics of apparently sporadic PA in a cohort of young patients. Clinical and molecular analysis of 235 patients (age ≤ 30 years) with PA. Clinicians from several Spanish and Chilean hospitals provided data. Genetic screening was performed via next-generation sequencing and comparative genomic hybridization array. Clinical variables were compared among paediatric, adolescent (<19 years) and young adults' (≥19-30 years) cohorts and types of adenomas. Phenotype-genotype associations were examined. Among the total cohort, mean age was 17.3 years. Local mass effect symptoms were present in 22.0%, and prolactinomas were the most frequent (44.7%). Disease-causing germline variants were identified in 22 individuals (9.3%), more exactly in 13.1 and 4.7% of the populations aged between 0-19 and 19-30 years, respectively; genetically positive patients were younger at diagnosis and had larger tumour size. Healthy family carriers were also identified. Variants in genes associated with syndromic forms of PAs were detected in a large cohort of apparently sporadic pituitary tumours. We have identified novel variants in well-known genes and set the possibility of incomplete disease penetrance in carriers of MEN1 alterations or a limited clinical expression of the syndrome. Despite the low penetrance observed, screening of AIP and MEN1 variants in young patients and relatives is of clinical value.

Novel somatic variants involved in biochemical activity of pure growth hormone-secreting pituitary adenoma without GNAS variant

We aimed to identify somatic genetic alterations in pure growth hormone (GH)-secreting pituitary adenomas without GNAS variants. Patients with GH-secreting pituitary adenoma who underwent transsphenoidal adenomectomy at Severance Hospital, Yonsei University College of Medicine were recruited. Somatic genetic alterations were profiled by whole-exome sequencing (WES) and targeted resequencing. WES was performed using DNA from nine GH-secreting pituitary tumors and corresponding blood samples. Absence of GNAS variant was confirmed by Sanger sequencing. For targeted resequencing of 140 fixed tissues, 48 WES-derived candidate genes and 7 GH-secreting pituitary adenoma-associated genes were included. Forty-eight genes with 59 somatic variants were identified by WES. In targeted resequencing, variants in 26 recurrent genes, including MAST4, PRIM2, TNN, STARD9, DNAH11, DOCK4, GPR98, BCHE, DARS, CUBN, NGDN, PLXND1, UNC5B, and COL22A1, were identified, but variants in previously reported genes were not detected. BCHE, DARS, NGDN, and UNC5B variants were associated with increased GH-secreting pituitary tumor biochemical activity, which was confirmed in vitro. Although recurrent point variants were rare, several somatic variants were identified in sporadic pure GH-secreting pituitary adenomas. Several somatic variants may affect pathways involved in the tumorigenesis and biochemical activities of GH-secreting pituitary adenomas.

Quantitative proteomics revealed the molecular characteristics of distinct types of granulated somatotroph adenomas.

Somatotroph adenomas are obviously heterogeneous in clinical characteristics, imaging performance, pathological diagnosis and therapeutic effect. The heterogeneity of the tumors, especially for SG and DG type adenomas, have attracted great interest in identifying the specific pathological markers and therapeutic targets of them. However, previous analyses of the molecular characteristics of the subtypes of somatotroph adenomas were performed at genomic and transcriptome level. The proteomic differences between the two subtypes of somatotroph adenomas are still unknown. Tumor samples were surgically removed from 10 sporadic pituitary somatotroph adenoma patients and grouped according to the pathological type. Tandem mass tag (TMT)-based quantitative proteomic analysis was employed to analyze the proteomic differences between SG and DG tumors. In total, 228 differentially expressed proteins were identified between SG adenomas and DG adenomas. They were enriched mainly in extracellular matrix (ECM)-receptor interaction, leukocyte transendothelial migration, arrhythmogenic right ventricular cardiomyopathy and DNA replication pathways. Protein-protein interaction (PPI) network analysis indicated that Cadherin-1 and Catenin beta-1 were the most important key proteins in the differences between SG and DG adenomas. Immunohistochemistry (IHC) confirmed the expression levels of the key proteins. This study provides large-scale proteome molecular characteristics of distinct granulation subtypes of somatotroph adenomas. Compared with DG adenomas, The differential protein of SG adenomas mostly enrich in invasive and proliferative functions and pathways at the proteomic level. Cadherin-1 and Catenin beta-1 play key roles in the different biological characteristics of the two tumor subtypes.

Apoplexy in sporadic pituitary adenomas: a single referral center experience and AIP mutation analysis.

To analyze the clinical, laboratory, and radiological findings and management of patients with clinical pituitary apoplexy and to screen for aryl hydrocarbon receptor-interacting protein (AIP) mutations. The clinical findings were collected from the medical records of consecutive sporadic pituitary adenoma patients with clinical apoplexy. Possible precipitating factors, laboratory data, magnetic resonance imaging (MRI) findings and treatment were also analyzed. Peripheral blood samples were obtained for DNA extraction from leukocytes, and the entire AIP coding region was sequenced. Thirty-five patients with pituitary adenoma were included, and 23 (67%) had non-functioning pituitary adenomas. Headache was observed in 31 (89%) patients. No clear precipitating factor was identified. Hypopituitarism was observed in 14 (40%) patients. MRI from 20 patients was analyzed, and 10 (50%) maintained a hyperintense signal in MRI performed more than three weeks after pituitary apoplexy (PA). Surgery was performed in ten (28%) patients, and 25 (72%) were treated conservatively with good outcomes. No AIP mutation was found in this cohort. Patients with stable neuroophthalmological impairments can be treated conservatively if no significant visual loss is present. Our radiological findings suggest that hematoma absorption lasts more than that observed in other parts of the brain. Additionally, our study suggests no benefits of AIP mutation screening in sporadic patients with apoplexy.

ACROMEGALY COMBINED WITH GIGANTISM ASSOCIATED WITH THE AIP-GENE MUTATION: A CLINICAL CASE

Pituitary gigantism is an extremely rare disorder: the incidence of pituitary tumors in children is approximately 0.1 in one million, and only about 1 to 10% of the pituitary tumors secrete the GH in childhood. Gigantism should be suspected if the patient's height is 3 standard deviations above the normal average height or 2 standard deviations above the corrected height of parents. When pituitary gigantism is suspected, the clinician should consider the presence of disorders, known to be associated with the GH-secreting pituitary tumors, including the McCune Albright syndrome (MAS), Carney complex (CNC), multiple endocrine neoplasia, types 1 and 4 (MEN 1, MEN 4), Familial isolated pituitary adenoma (FIPA), the paraganglioma, pheochromocytoma and pituitary adenoma association (PAA) due to succinate dehydrogenase defects, and X-linked acrogigantism (X-LAG). The molecular genetics of the AIP-associated FIPA, MAS, CNC, and MEN 1 has been extensively studied and reviewed, especially in children and young adults. The GH-secreting adenomas seem to be more invasive and aggressive in childhood than in adulthood. Data on a rare disease — gigantism combined with phenotypic signs of acromegaly in a young patient are presented. Clinical and laboratory parameters, data of histological and genetic analysis are described. Genetic analysis performed by AIP gene by Sequencing, proved a rare mutation in the locus of exons 1-6 of the AIP gene. The presented clinical case describes a rare fact of the AIP-gene mutation in the p.Cys238Tyr locus, which is associated with the occurrence of a giant pituitary adenoma in childhood. Aggressive growths of the pituitary tumor, its high proliferative and hormonal activity, clinical manifestations of gigantism in combination with severe phenotypic signs of acromegaly have also been noticed. Resistance to the therapy with somatostatin analogs has been revealed in this case. Considering the absence of genetic predisposition to a pituitary adenoma in the patient, this case can be regarded as a sporadic pituitary adenoma variant due to the abnormal AIP-gene expression and the disturbance of regulation during tumorigenesis.

Pituitary Adenomas Evade Apoptosis via Noxa Deregulation in Cushing's Disease

Introduction: Sporadic pituitary adenomas are common (>10%) in the general population. Microadenomas (< 1 cm across) can become symptomatic with adrenocorticotropin oversecretion causing Cushing’s disease (CD), leading to high morbidity and mortility. Pathogenic mechanisms in a majority of adenomas including wildtype CD adenomas remain unknown. Mechanistic studies are hindered by a lack of in-vitro models and normal human pituitary gland controls. We hypothesized that comparative analysis of human adenomas with syngeneic normal pituitary glands could reveal pathogenic mechanisms driving CD. Methods: We surgically annotated adenomas and en-route adjacent normal glands in 34 patients. We performed single cell RNAseq and captured 28,724 cells in 6 patients (3 CD and 3 non-CD; 5 pairwise), bulk RNAseq in 7 patients (5 CD and 2 non-CD; 5 pairwise) and DNA methylation analysis in 6 patients (3 CD and 3 non-CD). We confirmed the mechanisms of sporadic CD adenoma pathogenesis in 2 additional syngeneic pairs of human cell lines and using a novel murine normal corticotroph-enriched cell line. Results: Using marker-based classification, we confirmed canonical resident cell classes including corticotrophs in the human pituitary gland. We found SOX2+/S100B+ folliculostellate cells which play a role in pituitary cell replenishment and homeostasis in the normal gland but not in the adenoma compartment. Within the terminally differentiated corticotrophs in the adenoma compartment, we discovered a subset of proliferating cells with upregulation of canonical oncogenes, histone modifiers and DNA repair genes. We also found that consensus dominant genes including PMAIP1 (encoding the pro-apoptotic BH3 only Bcl-2 protein noxa) sharply demarcated adenoma cells from normal gland. The PMAIP1 locus was hypomethylated in CD adenomas compared to non-CD samples. However, despite epigenetic and transcriptional upregulation, we found proteasomal degradation of noxa protein in CD adenomas. Using the selective proteasomal inhibitor bortezomib, we were able to rescue noxa ex-vivo and in-vitro, induce apoptosis, and reduce cell survival of adenoma cell lines. Conclusions: We defined the transcriptionl and DNA methylation landscape of human pituitary adenomas compared to adjacent normal gland tissue. We identified proteasomal-mediated noxa degradation despite PMAIP1 overexpression as an escape mechanism from apoptosis in adenomatous corticotrophs. The proteasomal inhibitor bortezomib rescued noxa and induced apoptosis in adenoma cells, highlighting its potential as a novel therapeutic strategy in CD.

Exceptional Localization of a Prolactinoma as Part of Familial Isolated Pituitary Adenomas

The syndrome of familial isolated pituitary adenomas (FIPA) or predisposition to pituitary adenomas (PAP) is characterized by the presence within the same family of at least two isolated pituitary adenomas without any other type of associated endocrine tumor. These pituitary tumors may present as homogenous with the same tumor phenotype or heterogeneous with different patterns of pituitary tumor phenotypes (GH, Prolactine, ACTH secretion or non-functioning pituitary adenomas) within the same kindred. Patients with FIPA are significantly younger at diagnosis and have significantly larger pituitary adenomas than matched sporadic pituitary adenoma counterparts. We report the case of a prolactinoma attached to the pituitary stalk as part of FIPA, revealed by erectile dysfunction.

Germline mutations in MEN1 are associated with the tumorigenesis of pituitary adenoma associated with meningioma.

Pituitary adenoma and meningioma are two of the most common benign tumors in the central nervous system. Pituitary adenoma associated with meningioma (PAM) is a rare disease, the tumorigenesis of which remains unclear. Therefore, the aim of the present study was to investigate the tumorigenesis of PAM. A total of 8,197 patients with pituitary adenoma were analyzed. Furthermore, the clinical data of 57 patients with PAM were compared with patients with multiple endocrine neoplasia 1 (MEN-1) syndrome. Whole exome sequencing (WES) was performed on 23 samples from patients with PAM and the germline mutation was verified by Sanger sequencing. The age of tumor penetrance (age of patients at diagnosis) for PAM was significantly higher than that for patients with MEN-1. Compared with MEN-1 patients, there was a significant association between PAM and female sex (P=0.004). Clonal analysis and phylogenetic tree construction suggested that the pituitary adenoma and meningioma in PAM don't originate from a common progenitor. WES revealed that 5/23 PAM samples had the recurrent germline mutation MEN1 c.1523G>A; p.G508D, which may be a genetic risk factor for PAM. Compared with patients with sporadic pituitary adenoma, the difference was statistically significant (P=0.0004). Compared with wild-type MEN1, there was a significant association between the MEN1 mutation and recurrence of pituitary adenoma, young age and larger diameter of the meningioma. The present study indicated that germline mutations in MEN1 may be associated with the tumorigenesis of PAM.