A Novel and Rare Pathogenic Gene Variant in 2 Patients With Multiple Endocrine Neoplasia Type 1 (MEN-1) Syndrome.

Multiple endocrine neoplasia type 1 (MEN-1) is a syndrome characterized by development of tumors including parathyroid adenomas, duodenopancreatic neuroendocrine tumors, and pituitary adenomas. We describe 1 patient with a novel and another with a rare pathogenic MEN-1 variant. Case 1 was a 61-year-old woman with recurrent hypercalcemia who ultimately required a subtotal parathyroidectomy, with a thymectomy revealing a thymoma. She then developed a gastrinoma requiring pancreatectomy and also had a biochemically nonfunctioning sellar mass. Genetic testing found a novel MEN1:c.1192delC, p.(Gln398Argfs*47) pathogenic variant. Case 2 was a 38-year-old woman with a family history of MEN-1, who had recurrent hypercalcemia and nephrolithiasis requiring a subtotal parathyroidectomy. She had a macroprolactinoma, but no pancreatic lesions. Genetic testing found a rare MEN1:c.784-9G > A pathogenic variant. MEN-1 syndrome should be considered in patients presenting with 1 or more classical MEN-1-associated tumors based on clinical suspicion.