Pituitary Adenomas Research Articles

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

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

Hypofractionated Gamma Knife Radiosurgery in Big Tumors

Objective: This research aimed to determine the most effective dosages and achieve improved outcomes without surgical intervention, discomfort, or blood loss. Its objective was also to regulate the formation of both benign and malignant tumours and reduce tumour size. Patients and Methods: A study involving 50 patients at Dr. Saad Al-Witry Hospital for Neurosciences and Al-Altaj Hospital examined brain tumours using MRI models, CBCT, and a gamma knife device. Patients with large tumours were included, while those receiving single fractions of treatment and pregnant women were excluded. Patients were prepared using Leksell frames, thermoplastic masks, and personalised stereotactic masks. Gamma Knife radiosurgery sessions were administered based on tumour size, location, and patient tolerance. Results: This study analysed the use of hypofractionation gamma knife treatment for six brain tumours: Meningioma, Glioma, Schwannoma, Arteriovenous Malformations (AVM), Pituitary Adenoma, and Metastasis. The mean dose distribution was higher in metastasis, followed by AVM, meningioma, glioma, schwannoma, and pituitary adenoma. The maximum dose was found in metastasis, followed by meningioma, glioma, pituitary adenoma, AVM, and schwannoma. The coverage of the target reached excellent value for metastasis, followed by AVM and pituitary adenoma. The beam on time for the treatment was highest in meningioma. Following six months of treatment, the study found a significant difference in tumour volume before and after six months. The highest reduction was observed in meningioma cases, followed by glioma and vestibular schwannoma. A study involving ten patients showed a significant reduction in tumours after a year of gamma knife treatment, with meningioma cases showing the highest reduction. Conclusion: The study found that metastasis was the most common cancer, followed by meningioma, glioma, schwannoma, AVM, and schwannoma. After six months, meningioma showed the highest reduction, and meningioma showed a better response to hypofractionation, followed by AVM.

LONG-TERM NATURAL HISTORY OF GIANT NULL CELL PITUITARY ADENOMA.

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

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.

Detection and classification on MRI images of brain tumor using YOLO NAS deep learning model

If a brain tumor is not properly diagnosed, it might result in fatal consequences and major health issues. As a result, a key component of diagnosis is the early identification of brain tumors and the precise categorization of brain tumor types. This research work focusses on detection and classification such as pituitary, meningioma, glioma, and non-tumorous tumors from brain tumor MRI image using YOLO NAS model. Advances in deep learning have led to an increasing awareness of computer-aided diagnosis technology. To improve classification performance, the input data set is acquired from the REMBRANDT repository using the Digital Database of Brain Tumor Magnetic Resonance Images. The primary phases of this task include segmentation, classification, and pre-processing. The researcher preprocessed the RGB image to exclude any undesired spots before locating the ROI. For each brain tumor image, we used the hybrid anisotropic diffusion filtering (HADF) technique to remove noise. The Encoder-Decoder Network (En–DeNet), which uses a deep neural network based on U-Net as the encoder and a pre-trained EfficientNet as the decoder, is then used to segment the MRI images. A proposed model was developed using a deep learning-based YOLO NAS technique to identify brain cancers from MRI images such as meningioma tumors, non-tumor, glioma tumors, and pituitary tumors. The suggested model's classification performance is weighed based on parameters such as precision, F1-score, sensitivity, accuracy, and specificity. The proposed fusion method YOLO NAS has improved classification results of accuracy (AC = 0.997%), specificity (SP = 0.985%), precision (PR = 0.982%), F1-score (F1 = 0.992%), and sensitivity (SE = 0.985%) using 2570 MRI data for training and 630 data for testing and validation of brain tumor cases. The results show that the brain tumor type classification system based on the proposed YOLO NAS technique works better than the DNN, PDCNN, DenseNet-161, and DCNN-SGD model classifiers.

Radiomic Applications in Skull Base Pathology: A Systematic Review of Potential Clinical Uses

Objectives Radiomics involves the extraction and analysis of numerous quantitative features of medical imaging which can add more information from radiological images often beyond initial comprehension of a clinician. Unlike deep learning, radiomics allows some understanding of identified quantitative features for clinical prediction. We sought to explore the current state of radiomics applications in the skull base literature. Methods A systematic review of studies evaluating radiomics in skull base was performed, including those with and without machine-learning approaches. Studies were summarized into thematic elements as well as specific pathologies. Results A total of 102 studies with 26,280 radiographic images were included. The earliest radiomic study was published in 2017 with exponential growth in research since then. Most studies focused on tumor diagnosis (40.8%), followed by tumor prognosis (31.1%), automated segmentation (16.5%), other applications (7.8%), and lastly prediction of intraoperative features (3.9%). Pituitary adenomas (41.7%) and vestibular schwannomas (18.4%) represented the most commonly evaluated pathologies; however, radiomics could be applied to a heterogeneous collection of skull base pathologies. The average study included 258677 cases (range 4; 6755). Conclusion Radiomics offers many functions in treating skull base pathology and will likely be an essential component of future clinical care. Larger sample sizes, validation of predictive models, and clinical application are needed. Further investigation into the strengths and weaknesses of radiomic applications in skull base treatments is warranted.

Challenges in Managing Insulinomas and Hyperparathyroidism in MEN1: A Clinical Case Study

Pancreatic insulinoma is an uncommon neuroendocrine tumor with an incidence of approximately 1 per million people annually. While the majority of insulinomas are sporadic, a minority are associated with Multiple Endocrine Neoplasia type 1 (MEN1), a rare genetic disorder transmitted in an autosomal dominant pattern. MEN1 is characterized by the presence of hyperplastic or adenomatous parathyroid glands, pancreatic islet cell tumors, and pituitary tumors. The disorder can also involve lesions in the duodenum, adrenal glands, thymus, and bronchi. We report a case of MEN1 presenting with multiple insulinomas in a 37-year-old male, who exhibited symptoms of intermittent hypoglycemia over a decade. Diagnostic workup included biochemical assays , and imaging studies that revealed elevated insulin and C-peptide levels and hypervascular pancreatic lesions, , and pathological findings consistent with MEN1. Surgical intervention involved the enucleation of insulinomas and distal pancreatectomy, followed by removal of parathyroid adenomas. The postoperative evolution was marked by the resolution of hypoglycemic episodes and the persistence of primary hyperparathyroidism. This case underscores the complexity of diagnosing and managing insulinomas within the context of MEN1. It highlights the importance of a multidisciplinary approach to treatment and the need for ongoing surveillance to address both endocrine manifestations and psychological impacts. The findings advocate for comprehensive management strategies and support systems to improve patient outcomes and quality of life.

Acromegalia em felinos

Acromegaly in felines occurs mainly due to a pituitary adenoma of somatotropic cells, and presents slow and progressive evolution, responsible for increasing the production and secretion of growth hormones (GH). This condition is common in senile or adult male domestic cats, neutered and with short hair. The pathophysiology is due to the excessive release of GH in the adenohypophysis region, whose synthesis is regulated by growth hormone-releasing hormone (GHRH) and somatostatin, responsible for stimulating or inhibiting the secretory axis, respectively. The anabolic action of GH is responsible for increasing the secretion of IGF-1, which is mainly responsible for the clinical signs of acromegaly, such as body growth and organomegaly. The catabolic effect refers to insulin resistance. Clinical signs may be associated with secondary diabetes mellitus (DM), weight gain, exacerbated growth of various tissues and neurological signs as the tumor mass grows. The diagnosis of the disease can be performed through laboratory, imaging and endocrine tests such as the specific immunoassay for GH and/or insulin-like growth factor 1 (IGF-1). Treatment is based on controlling the DM that develops secondary to it, as well as on attempts to reduce or even inhibit the excess release of GH. Treatment can be performed with somatostatin analogues and dopamine agonists. The use of stereotactic radiotherapy can also be recommended, with favorable results for tumor reduction, as well as the surgical technique of transsphenoidal hypophysectomy, which presents better results than other techniques but is a complex surgical procedure. This project aims to inform veterinarians of this endocrine disease and its main currently recognized diagnoses and treatments, emphasizing the need to establish a differential diagnosis for difficult-to-control DM.

8342 A Rare Case of a Corticotropic and Gonadotropic Pituitary Double Adenoma

Abstract Disclosure: S. Gruber: None. D. Kirschenbaum: None. T. Hortobagyi: None. C. Serra: None. A. Bink: None. F. Beuschlein: None. Z. Erlic: None. Background: Pituitary adenomas account for about 15% of all intracranial neoplasms and typically arise from monoclonal proliferation of anterior pituitary cells. While lactotropic and clinically hormone-inactive adenomas make up by far the largest proportion, somatotropic and corticotropic adenomas have a significantly lower prevalence. This case describes the very rare finding of a corticotropic and gonadotropic double adenoma. Clinical Case: A 63-year-old Caucasian man (BMI 36.7 kg/m2) presented in the obesity clinic. Hypercortisolism was suspected by repeated lack of cortisol suppression in low-dose dexamethasone suppression tests [minimal 87 nmol/l] and disrupted circadian rhythm of cortisol secretion according to salivary cortisol profile. Cortisol levels in a 24-hour sample of urine were normal. ACTH levels were elevated [73 ng/l; n&amp;lt;61 ng/l] leading to suspicion of Morbus Cushing. Concomitant diseases include sleep apnea, arterial hypertension and newly diagnosed type 2 diabetes mellitus. Medical history was notable for deep vein thrombosis and pulmonary embolism. Other stigmata of hypercortisolism were not evident. The rest of endocrine work up confirmed partial secondary hypothyroidism and hypogondotropic hypogonadism. An MRI of the pituitary gland revealed a pituitary macroadenoma with a maximum dimension of 20 mm. The patient underwent an endoscopic transnasal adenomectomy with post-operative corticotropic insufficiency. Contrary to our expectations, the histological examination of the surgical resection revealed a gonadotrophic pituitary adenoma with SF1 and focal FSH expression. The discrepancy between clinical, biochemical and histological findings led to subsequent examinations of the specimen with detection of an small fragment accounting for less than 5% of the total sample with expression of T-Pit and ACTH but neither SF1 nor Pit-1, corresponding to an additional corticotropic adenoma with densely granulated pattern. The tumor cells did not show overlapping expression patterns of transcription factors or hormones, which indicates the coincidence of two distinct adenomas. Three months postoperatively, the patient is biochemically cured. Partial anterior pituitary insufficiency remained. Conclusion: Pituitary double adenomas are found in 0.5-1.5% of all surgical specimens. They are characterized by their origin from different cell lines, which distinguishes them from plurihormonal adenomas, which originate from one single cell line. Here we demonstrate a SF1-T-Pit lineage combination resulting in a neighboring ACTH and FSH-adenoma. In this particular case, the clinically relevant corticotropic adenoma was comparatively tiny, making it easy to miss. This illustrates well the importance of careful correlation of clinical, laboratory and histologic findings as correct diagnosis is crucial for postoperative patient management. Presentation: 6/2/2024

6400 An Unusual Presentation of Silent Corticotroph Pituitary Macroadenoma

Abstract Disclosure: N. Mon: None. V. Lohano: None. B. Williams: None. N. Lehman: None. R. Kulkarni: None. S.L. Mokshagundam: None. Silent Corticotroph Pituitary Adenomas (SCA) are a rare group of nonfunctioning pituitary adenomas (NFA) comprising 3-6% of all pituitary adenomas and up to 20% of corticotroph adenomas. SCA are biologically and clinically distinct from Cushing disease and NFA. SCA present with headache, visual field impairment, hypopituitarism, and pituitary apoplexy. We present a case of SCA with the initial presentation of syncope with undetectable ACTH and very low AM cortisol level.A 67 year-old-female was incidentally found to have a pituitary macroadenoma in MRI brain for syncope work up in 2017. MRI reported 1.4 x 1.2 x 1.3 cm sellar mass with suprasellar extension, minimal mass effect on the optic chiasm and no cavernous sinus invasion. Initial labs showed ACTH &amp;lt;5 (7.2-63.3 pg/mL), AM cortisol 0.8 (6-28ug/dl), Prolactin 101.1 (3.3-27 ng/mL), TSH 0.08 (0.34-5.60 uIU/mL), Free T4 0.6 (0.58-1.64 ng/dL), FSH 1.7 (2-5 mIU/mL), LH &amp;lt;0.2 (1-13 mIU/mL), IGF-1 33 ( 41-279 ng/mL). ACTH stimulation test: cortisol 0.5 ug/dl at baseline, 5.8 ug/dl at 60min. She was diagnosed with panhypopituitarism and hyperprolactinemia due to stalk effect. Hydrocortisone and Levothyroxine (LT4) were started. She underwent pituitary macroadenoma resection for optic chiasm decompression in 2017. Pathology reported pituitary neuroendocrine tumor (pitNET), but no immunostaining was done at that time. Follow up MRI in 2019 showed residual pituitary tumor. In 2023, she endorsed headaches, mood changes, fatigue and weight gain. Physical exam was unremarkable except BMI 34.75. Prolactin, Free T4, IGF-1 were normal. MRI in 2023 revealed recurrent and enlarging pituitary adenoma (1.9 x 1.4 x 1.6 cm) with suprasellar extension, abutting the optic chiasm, and left cavernous sinus invasion with internal carotid artery encasement. She underwent revision transsphenoidal resection of pituitary tumor to decompress the optic chiasm with plan for subsequent focused radiation to the cavernous sinus portion. Postoperative period was uneventful and hydrocortisone and LT4 were continued on discharge. Final pathology reported silent corticotroph lineage pitNET with low Ki67, immunostaining positive for TPIT, CAM5.2, and negative for ACTH. ACTH-negative SCA are a rare subtype and more likely to have lower ACTH levels, and multiple microcysts on MRI than ACTH-positive SCA. New WHO classification of pitNET highlights the histological typing and subtyping based on immunostaining of pituitary lineage transcription factors as the cornerstone for accurate classification. SCA are more biologically aggressive tumors with a high propensity of recurrence and resistance to conventional treatment. TPIT and ACTH immunostaining significantly improved the diagnosis of SCA and thereby close clinical follow up for early recognition and management of SCA recurrence. Absence of serum markers of recurrence makes this challenging. Presentation: 6/1/2024

8744 Genomic Variant Landscape In Aggressive &amp; Treatment Resistant Prolactin-Secreting Tumors

Abstract Disclosure: D. Marrero-Rodríguez: None. K. Taniguchi-Ponciano: None. F. Martinez-Mendoza: None. E. Peña-Martinez: None. S. Vela-Patiño: None. S. Hinojosa-Alvarez: None. J. Hernandez-Perez: None. R. Chavez-Santoscoy: None. E. Sosa-Eroza: None. P.E. Espinosa Cardenas: None. M. Mercado: None. Pituitary tumors (PT) represent the second most frequent intracranial tumor and this neoplasm arises from adenohypophyseal cells. Prolactin-secreting tumor (PRL-tumors) are the most commonly neoplasm of the pituitary gland and arises from lactotrophs, and account for 50% of all pituitary tumors. Pituitary tumors are highly heterogeneous lesions and many of them are invasive in up to 45%, with up to 15% being clinically aggressive. Aggressive PRL-tumors are defined as invasive tumors with unusually rapid growth rate despite maximal tolerated dopamine agonist dose and requiring additional therapy and presenting multirecurrent potential. Predicting pituitary tumor behavior remains a challenge, therefore we performed whole exome sequencing to identify genomic variant landscape from aggressive and treatment-resistant prolactin-secreting pituitary tumors. Interestingly one tumor showed one hotspot mutation in splicing factor gene SF3B1 (c.C1873T:p.R625C), a second tumor showed an stop codon in SF3B1 (c.C496T:p.R166*). We then evaluated known hereditary-related pituitary tumor genes, identifying three patients with two different GNAS allelic variants the first one showed c.A3059G:p.N1020S and two tumors with c.C1307A:p.A436D variants. PRKAR1A gene did not showed any allelic variants in our cohort, while all tumors presented c.A1636G:p.T546A variant in MEN1 gene, in AIP gene allelic variant c.C682A:p.Q228K was present in all tumors. PAX6 gene is related to pituitary gland development and function, we found a deletion (c.980delA:p.K327Rfs*29) causing frameshift present in all tumors. The target coding-gene for cabergoline, first line of treatment, DRD2 di not showed any allelic variant. Also XRCC1 and ABCB1 genes, which are related to drug and therapy response showed c.A1196G:p.Q399R and c.T2887G:p.S963A allelic variants in 100% and 88% of tumors, respectively. Together this genomic landscape could represent higher risk to harbor aggressive non-responsive PRL secreting tumor. Presentation: 6/1/2024

6555 Cabergoline-induced psychiatric symptoms in a patient with a pituitary macroadenoma

Abstract Disclosure: G.S. Patel: None. J. Prater: None. Cabergoline is a long-acting dopamine agonist that is used for the treatment of hyperprolactinemia, especially in pituitary macroadenomas. It reduces the levels of prolactin (PRL) but is also effective in reducing the tumor size and allows patients to avoid undergoing surgical resection of the mass. It commonly causes side effects such as abdominal pain, bloating, dizziness, and headaches. It rarely can cause new onset psychological side effects or an exacerbation of pre-existing mood and behavioral disorders. We present the case of a male on cabergoline therapy who had new-onset psychiatric symptoms that persisted even after treatment was discontinued. The patient is a 40-year-old male who was found to have a pituitary macroadenoma measuring 2.2 x 1.8 x 1.6 cm on brain MRI after a one-year history of headaches, dizziness, and hearing loss. His vital signs and physical examination were unremarkable. Laboratory investigations revealed a PRL of 1,072 ng/mL. He was started on cabergoline 0.25 mg twice a week which reduced levels of PRL to 465.3 ng/dL. Throughout the next year, his PRL levels remained persistently elevated to &amp;gt;100 ng/dL and the cabergoline dose was steadily increased to 1 mg three times per week. About a year into treatment he began experiencing significant emotional lability, a tendency to cry, and bursts of temper which required the addition of multiple psychiatric medications. After two years of continued psychiatric symptoms, there was an attempt to both reduce cabergoline doses and switch to escalating doses of bromocriptine, both of which resulted in a reduction of psychiatric symptoms but also significant increases in PRL levels. The patient’s mood symptoms returned shortly after switching back to cabergoline, especially with increased doses. He eventually underwent trans-sphenoidal resection for his treatment-resistant pituitary macroadenoma. He was taken off cabergoline before surgery with a significant reduction in his mood symptoms but continues to require psychiatric medications for lasting emotional lability. Although rare, psychiatric side effects of cabergoline have been documented and must be addressed if a patient develops them while receiving treatment. Our patient had a severe presentation of mood symptoms from cabergoline therapy that required multiple psychiatric medications in escalating doses to control. It not only affected his quality of life but also resulted in long-term consequences. It is recommended that patients with similar presentations should be continued on cabergoline with the addition of clozapine as it has less of an effect on PRL levels. Other treatment options also include aripiprazole and quetiapine. However, when patients have treatment resistant macroprolactinomas and are unable to tolerate cabergoline, one would have to consider surgical treatment options for the treatment of hyperprolactinemia from pituitary macroadenomas. Presentation: 6/1/2024

8263 Long-term Imaging Follow-up of Non-functioning Pituitary Adenomas

Abstract Disclosure: N. Mehrotra: None. M.M. Ross: None. A.S. Chilukuri: None. S. Eljamri: None. C. Ewing: None. S. Patel: None. V. Patel: None. L.B. Siegel: None. D. Sistla: None. R.K. Shariff: None. P.K. Fazeli: None. Pituitary adenomas are common, affecting ∼15% of the population. Once a pituitary adenoma has been identified on imaging, an evaluation is undertaken for pituitary hormone excess and for pituitary hormone deficiency in the setting of larger adenomas (typically 1cm in size or greater). Hormone-producing or functioning pituitary adenomas are typically treated with medical or surgical therapy, but non-functioning pituitary adenomas can be followed conservatively if they are not contributing to morbidity. The natural history of non-functioning pituitary adenomas has not been well characterized and therefore although guidelines recommend follow-up pituitary imaging, there are no specific guidelines addressing how frequently or for how long these lesions should be followed. Our aim was to describe the clinical history of non-functioning pituitary adenomas using long-term clinical data from a large academic health system. We identified 791 patients who met our inclusion criteria of having more than one brain/pituitary MRI performed at least 3 months apart with a suspected non-functioning adenoma identified on the initial MRI. Each medical record was individually reviewed to confirm whether the adenoma was non-functioning based on clinical/biochemical evaluation. Patients were a median [interquartile range] of 48.3 [34.4, 63.6] years of age at the time of first MRI and 65% (n=517) were women. At presentation, 66% (n=523) of the pituitary adenomas were microadenomas (&amp;lt; 1 cm in size) and 34% were macroadenomas (&amp;gt; 1 cm). All patients had an MRI repeated at least 3 months after the initial MRI with median time of total imaging follow-up of 39.8 [17.0, 75.6] months. During follow-up, 658 patients were noted to have a stable lesion or a decrease in size of the adenoma. Patients whose lesion was noted to grow on MRI were slightly older than those who did not have growth (growth: 57.1 [41.9, 70.3] years versus no growth: 46.8 [33.7, 62.3] years, p&amp;lt; 0.0001). There were no differences with respect to BMI, hypopituitarism, smoking history or alcohol use between those with growth versus those without growth. Seventy-eight patients (9.9%) had surgical resection of their adenoma during follow-up. The most common indication for surgery was growth of the lesion (n=27), followed by visual changes (n=22). In the patients with a microadenoma at presentation, 90.8% remained stable in size or decreased in size during a median follow-up of 43.2 [20.5, 78.6] months. Only 2.3% of patients with a microadenoma at presentation underwent surgical resection during follow-up. In conclusion, the majority of non-functioning pituitary adenomas remain stable during prolonged imaging follow-up. Further study is needed to determine predictors of growth of non-functioning pituitary adenomas. Presentation: 6/2/2024

7214 A Retrospective Cohort Study on Prevalence Of Pituitary Adenomas in MEN2

Abstract Disclosure: R. Ghosh: None. N. Behiri: None. J. Glod: None. S. Gubbi: None. J. Klubo-Gwiezdzinska: None. Background: Multiple endocrine neoplasia (MEN) syndromes are autosomal dominant and present with tumors in at least two or more endocrine organs. MEN2 syndromes that are driven by germline rearranged during transfection (RET) gene pathogenic variants are divided into 2A consisting of medullary thyroid carcinoma (MTC), parathyroid adenomas and pheochromocytoma and 2B presenting with MTC, pheochromocytoma, marfanoid habitus, mucosal neuromas and gastrointestinal ganglioneuromatosis. Pituitary adenomas have been rarely described in MEN2 and hence we conducted a retrospective chart review to determine their prevalence in MEN2. Methods: Retrospective chart screening of MEN2 patients followed at a tertiary referral center between August 1999- August 2022 was done to evaluate the prevalence of pituitary adenomas using biochemical hormonal evaluation and magnetic resonance imaging (MRI) of pituitary based on screening of clinical symptoms. Results: The study consisted of 91 patients (43 MEN2A and 48 MEN2B), aged 35.3±16.9 years (MEN2A) and 18.6±6.4 years (MEN2B), 20/43 (46.5%) women in MEN2A and 24/48 (50%) women in MEN2B. These patients were followed for median duration of 6.5 years (3.3-22) in MEN2A and 8.5 years (5.4-14.6) in MEN2B. RET mutation status was unavailable for 1 MEN2A patient out of 91 patients. Among MEN2A patients, majority (53.5%) were positive for RET C634X mutation followed by RET 804, 609, 631,620 and 666 mutations in the descending order. While in MEN2B cohort all patients were positive for M918T RET mutation. A total of 4/91 (4.4%) patients were found to have pituitary adenomas (3 MEN2B and 1 MEN2A). One patient had clinically symptomatic ACTH producing microadenoma which was surgically resected, and others have asymptomatic non-functioning adenomas. The patient with Cushing’s disease underwent three transsphenoidal resections leading to complete resolution but developed panhypopituitarism. Prevalence of pituitary adenomas in our cohort was significantly higher than the general population screened based on clinical suspicion (p&amp;lt;0.001). Conclusion: Prevalence of clinically symptomatic pituitary adenomas is 1 in 1000 in the general population (1). It is rarely associated with MEN2 syndromes and only few cases are reported in the literature (2). However, screening of all patients with MEN2 for pituitary adenomas, regardless of clinical suspicion, might lead to incidental discovery of asymptomatic pituitary pathology and can provide the actual prevalence. Further studies are needed to evaluate the genetics of these pituitary adenomas in MEN2 syndromes to investigate whether RET protooncogene is indeed the dominant molecular driver of these tumors.

7559 TRIM21 Regulates Activation of ERK1/2 to Promote Growth and Drug Resistance in Pituitary Neuroendocrine Tumors

Abstract Disclosure: Y. Liu: None. F. Liu: None. C. Li: None. T. Zhang: None. L. Xue: None. Z. Wu: None. Objective: To investigate the role of the TRIM family genes in pituitary neuroendocrine tumors (PitNETs) and provide new targets and strategies for the clinical treatment of these tumors. Methods: A CRISPR screening system targeting the TRIM family was constructed and validated using next-generation sequencing. Stable cell lines overexpressing or knocking out TRIM21 were generated, and functional validation was performed using assays such as CCK-8, colony formation, and xenograft tumor growth in nude mice. RNA-seq, mass spectrometry, immunohistochemistry, and immunoblotting were employed to explore the signaling pathways and mechanisms underlying TRIM21's actions. Immunoprecipitation, immunofluorescence, GST-pulldown, NanoBiT assays, and ubiquitination experiments were conducted to investigate the effects of TRIM21 on ERK1/2. Immunohistochemistry and immunoblotting were used to explore the role of TRIM21 in drug- resistant prolactinomas and the correlation between TRIM21 and p-ERK. Results: Through screening the proliferative and drug-resistant effects of the TRIM family in MMQ and GH3 cells, we found that knocking out TRIM21 may inhibit cell growth and enhance drug sensitivity. Subsequently, stable cell lines overexpressing or knocking out TRIM21 were generated in MMQ and GH3 cells, revealing that TRIM21 overexpression promotes pituitary tumor cell growth and resistance to drug treatment, while TRIM21 knockout inhibits cell growth and enhances drug sensitivity. Cell-derived xenograft models showed that TRIM21 overexpression promoted growth of GH3 cells in vivo and resistance to cabergoline (CAB), while TRIM21 knockout suppressed growth of MMQ cells in vivo. Further exploration of the signaling pathways influenced by TRIM21 revealed that TRIM21 knockout downregulates the MAPK signaling pathway, while TRIM21 overexpression upregulates it. TRIM21 overexpression upregulates p-ERK1/2 in the MAPK pathway, while TRIM21 knockout decreases p-ERK. However, there is no significant influence on ERK1/2, JNK, p-JNK, p38, or p-p38. Mechanically, TRIM21 interacted with ERK1/2, enhancing the K27-linked ubiquitination of ERK1/2 and promoting their interaction with MEK1/2. In addition, the TRIM21 with D-docking mutant or ERK1/2 with CD-domain mutant resulted in the loss of their interaction. Furthermore, TRIM21 and p-ERK levels were significantly elevated in drug-resistant prolactinomas and immunohistochemical semi-quantitative analysis demonstrated a positive correlation between TRIM21 and p-ERK. Conclusion: The ubiquitin ligase TRIM21 catalyzes K27-linked ubiquitination of ERK1/2, enhancing its interaction with MEK1/2 and activation, thereby promoting growth and drug resistance in pituitary neuroendocrine tumors. TRIM21 may serve as a potential target for the treatment of pituitary neuroendocrine tumors. Presentation: 6/3/2024

6566 Concurrent Papillary Craniopharyngioma and Growth Hormone-Secreting Pituitary Adenoma: A Rare Collision Tumor

Abstract Disclosure: A.J. Mancini: None. R. Mathew: None. J. Oentoro: None. A.M. Devine: None. C. Maxwell: None. I. Kravets: None. Introduction: Collision tumors, which consist of two or more histologically distinct tumors in the same anatomic location, are rare; when occurring in the sella, they more commonly consist of a pituitary adenoma and Rathke cleft cyst. Here, we present a case of a collision tumor consisting of a papillary craniopharyngioma and GH-secreting pituitary adenoma. Clinical Case: A 49-year-old man presented with two months of headaches and blurry vision. Physical exam showed frontal bossing, enlarged jaw and hands, and macroglossia. A visual field exam revealed bitemporal hemianopsia. Initial labs included PRL 105.2 ng/mL (4.0-15.2), TSH 0.399 uIU/mL (0.27-4.2), free T4 0.95 ng/dL (0.93-1.70), FSH 0.8 mIU/mL (1.5-12.4), LH 0.3 mIU/mL (1.7-8.6), total testosterone 10 ng/dL (300-890) drawn at 6:00 a.m., cortisol 8.5 ug/dL (6.0-18.4) and ACTH 32.1 pg/mL (7.2-63.3) drawn at 10:30 a.m.; an IGF-1 was not initially sent. Pituitary MRI showed a 4.1 cm mixed solid and cystic sellar/suprasellar mass with mass effect on the optic chiasm. The patient underwent a craniotomy with tumor resection on hospital day (HD) 5 with pathology showing a papillary craniopharyngioma. The next week, an elevated IGF-1 level of 517 ng/mL (68-225) prompted a GH suppression test. GH levels 1 and 2 hours after oral glucose load were 19.3 ng/mL (0.05-3.00) and 17.8 ng/mL respectively, confirming the diagnosis of acromegaly. On HD 20, repeat MRI showed an interval increase in the mass size with increased mass effect on the optic chiasm. A second craniotomy with an endoscopic resection of the mass was performed, with pathology again showing a papillary craniopharyngioma. Post-operative MRI showed a residual mass with mild mass effect on the optic chiasm for which the patient began radiation therapy. Interval MRI demonstrating a further increase in the tumor size plus a rising IGF-1 level of 700 ng/mL and ongoing lack of GH suppression with an oral glucose load prompted a transsphenoidal resection of the tumor on HD 54. The pathology showed a growing residual papillary craniopharyngioma and a component of a PIT1 lineage adenoma, the majority of which expressed GH. The patient developed numerous complications during his hospitalization and ultimately passed away on HD 64. Conclusion: There are 22 reported cases of collision tumors of pituitary adenomas and craniopharyngiomas, and only five secreted GH. Moreover, four of the five cases described collision tumors with an adamantinomatous craniopharyngioma; the fifth case did not include data on the type of craniopharyngioma (1). Therefore, to the best of our knowledge, our case represents the first collision tumor of a GH-secreting pituitary adenoma and papillary craniopharyngioma. Reference: (1) Hasegawa H, Jentoft ME, Young WF, et al. Collision of Craniopharyngioma and Pituitary Adenoma: Comprehensive Review of an Extremely Rare Sellar Condition. World Neurosurg. 2021;149:e51-e62. Presentation: 6/3/2024

7295 Giant Pituitary Adenoma with Rapid Symptomatic Progression and Postoperative Mortality

Abstract Disclosure: R.D. Kennedy: None. M. Nicholson: None. Introduction: Giant pituitary adenomas, defined as pituitary adenomas measuring greater than 4 cm, present a therapeutic challenge because of their size, clinical features, and increased potential for complications following surgical intervention. Early detection and intervention to prevent growth and progression is paramount. We present a case of a patient with a giant 6.3 cm pituitary adenoma who had significant neurologic compromise, requiring surgical intervention, with resultant postoperative complications and death. Case:Patient is a 41 year old male with known history of pituitary adenoma who presented on 11/1/2023, from outside hospital, to the Neuroendocrine clinic with complaints of excessive truncal obesity, impotence, fatigue, and apathy. Vital signs were within normal limits. Physical exam revealed clouding of consciousness, grossly intact cranial nerve function, truncal obesity, and diminished power, tone, and bulk of the extremities. Formal visual field testing revealed bitemporal hemianopsia. A head CT scan revealed a 6.3 cm sellar mass with expansion of the sella, invasion of soft tissue into the sphenoid sinus, and extension of soft tissue cranially to the level of the third ventricle eccentric to the left. There was no evidence of apoplexy. Lab results revealed Prolactin of 924 ng/mL. The patient had been taking Bromocriptine, 2.5 mg daily, for at least three weeks. Less than three weeks after his initial evaluation, he returned to the hospital with complaint of acute ataxia. Pituitary MRI revealed 6.3 cm sellar mass with evidence of acute and subacute blood products, stretching of the optic chiasm from mass effect, extension into the bilateral cavernous sinuses, superior left MCA displacement, posterior left PCA displacement, 5 mm midline shift, uncal herniation and descending transtentorial herniation. The patient underwent endoscopic transsphenoidal resection with subsequent craniotomy for debulking. Postoperatively, he developed new right sided hemiplegia with aphasia with subsequent MRI finding of watershed infarct at the left MCA/PCA lateral posterior border zone territories with increasing mass effect over a 30 day hospital stay. He developed progressive global edema with worsening uncal and tonsillar herniations. Brain death was pronounced on 11/30/23. Discussion:This case highlights the importance of early intervention in patients with giant pituitary adenomas. Our patient had been experiencing right sided weakness for at least one year prior to his admission to our facility. In this case, earlier treatment with a dopamine agonist may have decreased the size of the adenoma or prevented rapid growth. This may have precluded the need for surgical intervention on an adenoma of this size, which carries increased risk for postoperative complications. Presentation: 6/2/2024

8308 Up-regulation of Diacylglycerol kinase gamma (DGKG) in aggressive recurrent pituitary tumors could be targeted by Dasatinib reducing cell proliferation and induced apoptosis

Abstract Disclosure: K. Taniguchi-Ponciano: None. I. Remba: None. M. Loza-Mejia: None. J. Salazar: None. A. Mendez-Perez: None. C. Aguilar-Flores: None. A. Chavez-Gonzalez: None. E. Ortiz-Reyes: None. L. Bonifaz: None. D. Marrero-Rodríguez: None. M. Mercado: None. Pituitary tumors (PT) represent 15% of all intracranial tumors. Some PTs exhibit an aggressive behavior, growing rapidly and invading surrounding tissues, and are frequently resistant to multimodal treatment showing multiple recurrences. Pituitary tumors often recur after initial surgery, particularly when invasive, precluding complete resection of the lesion, which can only be achieved in ∼40-50% of all patients.We have previously characterized transcriptome and exome from 22 tumor lesions from 11 patients by RNA- and DNAseq and methylome profile by microarrays of aggressive, both primary and recurrent PT from the same patient to identify molecular pharmacological targets.Among the differentially expressed genes in most recurrent tumors we found those related to fatty acid biosynthesis and metabolism, phosphatidylinositol, glycerophospholipid and phospholipase D signaling. Importantly, one gene found in most of the lipid-related pathways was diacylglycerol kinase gamma (DGKG). DGKG gene expression was confirmed by immunofluorescence and did not seem to be regulated by DNA methylation. And DGKG showed allelic c.G947A:p.R316K variant in all primary and recurrent tumor tissues analyzed, more research is needed to understand genetic variant impact on protein function. We then performed DGKG molecular docking for FDA-approved drug repurposing. Human DGKG tridimensional model was downloaded from AlphaFold and Autodock Vina, Molegro Virtual Docker, PyMol v2.5.2 program and the Protein-Ligand Interaction Profiler web tool were used. The in silico ADMET profiles were generated in ADMETLab 2.0 using only FDA approved drugs. We identified Dasatinib as a strong candidate for DGKG targeting. We then exposed GH3 cell line to increasing concentrations of Dasatinib (1, 2.5 y 5 μM) using DMSO as vehicle. After cell viability was assessed, approximatively 31% of all live GH3 cells were at proliferative state without any treatment, that was taken as our basal quantity to compare the GH3 cells treated with the TKI’s. Dasatinib reduced approximatively 28% the cell proliferation at 1 μM (p=0.0048), at 2.5 μM reduced nearly 50% of cell proliferation (p=0.003) and at 5 μM inhibited nearly 98% of cell proliferation (p=0.0395) by means of Click-iT EdU Cell proliferation Kit. We then, evaluated Dasatinib apoptosis induction capacity. Interestingly, the 1 μM Dasatinib concentration induced apoptosis (p=0.0001) as concentrations increased, cell death also increased considerably (p=0.0001) measured by Anexin V-FITC and DAPI assay. The RNAseq data from GH3 cells exposed to Dasatinib show diminished gene expression of cell cycle related genes and glycolysis.In conclusion, we observed DGKG upregulated in recurrent aggressive pituitary tumors participating in lipid metabolism pathways and could be targeted by Dasatinib at very low doses. Presentation: 6/3/2024

12562 Extraocular Muscle Enlargement With Proptosis In A Patient With Non Thyroidal Disease

Abstract Disclosure: S.S. Bantu: None. P.N. Kabir: None. A. Gondhi: None. T.B. Vaughan: None. Extraocular muscle enlargement with proptosis in a patient with Nonthyroidal disease Introduction: Majority of cases with extraocular muscle enlargement (EOME) is due to Graves’ disease, commonly in about 95% cases and another 5% make up other causes including inflammatory, neoplastic, vascular, infectious and acromegaly. We present a patient with sudden loss of vision, retroorbital pain with visual field deficits found to have EOME and subsequently a pituitary macroadenoma on imaging. Case: We present a 54-year-old male with history of hypertension, obstructive sleep apnea and morbid obesity who presented to us with complains of left sided vision loss. Patient was evaluated by ophthalmology and noted to have unilateral, left-sided, change in visual acuity. Physical exam was notable for macrognathia, skin tags, enlarged hands, excessive sweating. MRI brain revealed bilateral EOME with proptosis and a pituitary macroadenoma measuring 1.5x1.7x1.3cm, abutting the pre-chiasmatic left optic nerve. On biochemical evaluation he was noted to have elevated IGF1 of 979 confirming the diagnosis of acromegaly. ((hemoglobin A1C of 5.5%, prolactin 5.1, FT4 0.89, TSH 0.692, total testosterone 61, IGF1 level was 979)). He underwent transsphenoidal resection of the pituitary macroadenoma. Pathology showed sparsely granulated somatotroph adenoma. Discussion: Acromegaly has an incidence of 3-4 cases per million per year. The characteristics of the disease are due to chronic growth hormone hypersecretion resulting in the excessive growth of tissue due to the stimulation of insulin-like growth factor 1 (IGF-1). EOME with proptosis in acromegaly is seen rarely. Visual symptoms may manifest as visual field deficits due to compression of the optic pathway in 18-25% cases, increased intraocular pressure, increase in corneal thickness and a diffuse symmetrical enlargement of the extraocular muscles which cannot be distinguished from thyroid orbitopathy on imaging. The degree of enlargement appears to correlate with the duration of the disease rather than the levels of IGF1. EOME improves with the treatment of acromegaly. Although visual symptoms may be a rare presentation of acromegaly, if the clinical suspicion exists, one may consider obtaining an IGF-1 level to complete the evaluation of EOME if the thyroid levels are normal. Presentation: 6/3/2024

7102 Pituitary Apoplexy with Eventual Complete Tumour Involution

Abstract Disclosure: A. Ng: None. R. Lai: None. Pituitary apoplexy is an endocrinological emergency resulting from infarction or haemorrhage of the pituitary gland. We present a case of pituitary apoplexy from a non-functioning pituitary macroadenoma, complicated by pituitary insufficiency and subsequent tumour involution. An 80-year-old gentleman presented to the Emergency Department with sudden severe headaches and persistent vomiting and admitted for further evaluation. Computed tomography (CT) imaging of the brain showed a prominent pituitary gland and magnetic resonance imaging (MRI) confirmed a large sellar hyperintense lesion containing blood and proteinaceous material. It measured 1.6 cm by 1.2 cm by 1 cm and indented the optic chiasm. CT angiography did not reveal any aneurysms or intracranial haemorrhage. There were no neurological or visual field deficits at presentation. There was no indication for surgery upon neurosurgical consultation. Initial evaluation of the pituitary axis was consistent with central hypocortisolism (cortisol 75 nmol/L, adrenocorticotropic hormone 1.4 pmol/L [reference range (RR) 1.6-13.9]) and hypoprolactinaemia (prolactin 56 mIU/L, RR 73-351). Luteinising hormone levels were &amp;lt; 1 IU/L (RR 1-9); follicle stimulating hormone levels were 3 IU/L (RR 1-19) and testosterone levels were &amp;lt; 1 nmol/L (RR 5 to 30) as the patient was on androgen deprivation therapy for prostate cancer. Hydrocortisone was started and he was monitored for development of frank diabetes insipidus. He did not require regular desmopressin. He later developed anti-diuretic hormone mediated hyponatraemia (serum sodium nadir of 125 mmol/L, serum osmolality 275 mmol/kg, urine osmolality 390 mmol/kg) that was managed with fluid restriction and solute loading. He also developed central hypothyroidism on day 19 of admission (free thyroxine 11 pmol/L, thyroid stimulating hormone 0.49 mIU/L, RR 0.45-4.5) and oral levothyroxine was started. He was discharged with oral hydrocortisone and levothyroxine replacement. A repeat MRI of the pituitary 2 months later showed complete resolution of the mass and resolution of the mass effects. He was kept on oral hydrocortisone and levothyroxine replacement with regular follow-up.Most pituitary macroadenomas are non-functional, and can present with complications of apoplexy, mass effects or hormonal disturbances. However, the natural history of non-functional macroadenomas is not well known as most are operated on. Spontaneous regression of the tumour can rarely occur, notably in the setting of apoplexy and lymphocytic hypophysitis. Recovery of the pituitary axis may also accompany tumour regression. As spontaneous remission of pituitary macroadenomas may occur, close observation of tumours without visual field defects or significant mass effects may be an alternative to surgery. Presentation: 6/1/2024 12:15:00 PM