SUN-286 - A Case of MEN 1 with Development of Hyperparathyroidism and Pancreatic Neuroendocrine Tumor

Multiple Endocrine Neoplasia Syndrome Type 1 (MEN 1) is a rare autosomal dominant disorder which affects roughly one in thirty thousand people. This disorder is associated with a lifelong risk of both endocrine (primarily pituitary, pancreas, adrenal, and parathyroid) and nonendocrine neoplasias requiring close monitoring. Due to this, early screening of patients and their family members is necessary.

A 23-year-old female with no significant past medical history was found to have hypercalcemia with a calcium of 10.9 mg/dL (8.4-10.3 mg/dL), albumin of 4.3 g/dL (3.5-5.0 g/dL), and with elevated parathyroid hormone of 134 pg/mL (8.5-77.1 pg/mL). Urinary calcium was 250 mg/24 hrs. Vitamin D level was initially low at 22 ng/mL (30-80 ng/mL) with normal GFR > 60. However, after Vitamin D was repleted to a normal level of 30 ng/mL, PTH level remained elevated at 109 pg/mL with calcium of 11.1 mg/dL. She denied history of nephrolithiasis or fractures. She was referred to endocrine surgery for evaluation for parathyroidectomy given her age at diagnosis. On further history she did note that both her father and sister had hyperparathyroidism. Due to this, she underwent genetic testing which was significant for c.231 C>G gene variant consistent with diagnosis of MEN 1. Her father and sister also underwent genetic testing with similar results. She underwent right superior and right inferior parathyroidectomy with endocrine surgery but surgery was then halted due to concern for vocal cord paralysis. PTH level was persistently elevated following this and she is planned for re-exploration once vocal cord paralysis resolves. Further work up for other neoplasia was notable for 2.1 cm pancreatic tumor noted on CT abdomen/pelvis with atrophy of the body and tail of her pancreas secondary to chronic ductal obstruction. Dotatate PET/CT confirmed suspicion for pancreatic neuroendocrine tumor. She was referred to oncology with work up notable for normal for insulin, gastrin, vasoactive intestinal peptide (VIP), and glucagon levels. Chromogranin A level was also within normal range. Biopsy of this lesion was confirmatory for neuroendocrine tumor cells. She was offered surgical intervention for this lesion as well but opted for medical management due to ongoing plans for parathyroid surgery. She was started on lanreotide therapy with stable findings of her pancreatic lesion on two month follow up scans.

This case highlights the importance of thorough evaluation of patients presenting with singular endocrine neoplasia as proper history and genetic evaluation may lead to the discovery of syndromes requiring further work up. This is important not only for individual patients but also, as seen in this case, for the proper diagnosis and screening of family members.

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