Endocrine Abstracts

Introduction: Multiple endocrine neoplasia type 1 (MEN1) is a rare, autosomal dominant inherited syndrome caused by mutations in the MEN1 tumor suppressor gene and is characterized by the occurrence of parathyroid, pancreatic islet and anterior pituitary tumors. We present the case of a female patient known to have pituitary and parathyroid tumors in a MEN1 syndrome evolving for more than 20 years before associating pancreatic neuroendocrine tumor.

Case report: At the age of 18, our patient was diagnosed with a prolactinoma, which debuted with secondary amenorrhea, galactorrhea and symptoms of mass effect. After initiation of dopamine agonists, she had more than 50% shrinkage of tumor mass and remission of galactorrhea, but persistent high levels of prolactin. Because she refused both surgery and radiotherapy, she was maintained on a regimen of high dose of dopamine agonist. During further workup, she was diagnosed with primary hyperparathyroidism at the age of 33 and at the time of diagnosis our patient had undergone removal of only on gland that seemed to be affected at parathyroid scintiscan. Pathology confirmed an adenoma of the right lower parathyroid. Genetic screening confirmed germline menin mutation. During regular follow up, at the age of 45, she was diagnosed with a large pancreatic mass (2.73/2.61/3.16) cm and biopsy revealed a well differentiated neuroendocrine pancreatic tumor. In MEN I patients the most common found pNET are gastrinomas, usually developed in the duodenum and, although family history was positive for gastrinoma in her mother, maternal grandfather and brother, our patient developed a nonfunctioning neuroendocrine tumor. This case demonstrates the extremely varied phenotypic clinical patterns, even within the same family. The patient eventually underwent cephalic pancreaticoduodenectomy and pathology confirmed a neuroendocrine tumor classified as intermediate grade (KI67 10%, NEN G2). So matostatin receptor immunohistochemistry revealed a moderately positive score>66% of tumor cells and the patient was initiated treatment with somatostatin receptor analogue. Although the role of surgery for non-functioning pancreatic tumors remains controversial, malignant pancreatic neuroendocrine tumors are a major cause of death in MEN1 patients and most consensus recommend surgery for tumors that are more than 1–2 cm in size and/or show significant growth over 6–12 months.

Conclusion: We present the case of a patient that exhibits the classic history of MEN I syndrome, including prolactinoma, parathyroid adenoma and nonfunctional neuroendocrine pancreatic tumor. This case illustrates the considerable phenotypic variability of tumor type manifestations even in the same family.