Endocrine Abstracts

Introduction: Neuroendocrine tumors (NETs) are a heterogeneous group of rare neoplasms that originate from endocrine cells with the ability to secrete amines and hormonal polypeptides. Pancreatic neuroendocrine tumors (PNETs) can be functional or non-functional. Functional PNETs secrete common hormones such as gastrin, insulin and glucagon and much less frequent hormones such as vasoactive intestinal peptide (VIP). Their clinical characteristics depend on the peptide secreted. It is estimated that up to 10% of all pNETs being associated with MEN1.

Case report: We present the case of a 45-year-old woman who came to the emergency department with diarrhea, dehydration and electrolyte disorders (severe hypokalemia and hypercalcemia). The patient reported ~5 daily episodes of diarrhea without mucus or blood for 7 months while the last month she mentioned an increase to ~15 daily episodes of diarrhea with fatigue, polydipsia and polyuria. Due to the hypercalcemia, further testing was compatible with the diagnosis of primary hyperparathyroidism. 99 Tc-sestamibi scanning for parathyroid gland evaluation revealed features suggestive of parathyroid adenoma. Contrast-enhanced computed tomography of the abdomen, as part of the workup for the chronic diarrhea, showed 3 masses in the pancreatic body and tail. Biopsy guided by ultrasound was performed and the cytological examination revealed a neuroendocrine carcinoma of the pancreas. Given this history and imaging findings, a workup for MEN1 was initiated. Magnetic resonance imaging (MRI) of pituitary gland showed a pituitary macroadenoma measuring 16 × 17 x 13 mm while the laboratory investigation was compatible with the diagnosis of acromegaly. The genetic test was positive for MEN 1 syndrome both for the patient and her three children.

Conclusion: Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant hereditary tumor syndrome with a high degree of penetrance, that is caused by inactivating mutations of the tumor suppressor gene MEN1, and is characterized by a predisposition to a multitude of endocrine and nonendocrine tumors Our patient demonstrates a classic example of MEN1 syndrome with tumors in all 3 defining endocrine organs, including pituitary macroadenoma, parathyroid adenoma, and pancreatic neuroendocrine tumors. When the diagnosis of the syndrome is done, genetic testing of first-degree relatives is considered necessary