A Case of Asymptomatic Multiple Endocrine Neoplasia Type I with Thymic Carcinoid

ABSTRACT

Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant hereditary disorder caused by germline mutation of the MEN1 gene. It is characterized by tumors of the anterior pituitary gland, parathyroid glands, and endocrine pancreas. Thymic carcinoid tumor is uncommon and associated with a high mortality, but its natural history has not been investigated yet. We report a case of asymptomatic MEN 1 with a thymic carcinoid tumor. A 37-year-old man underwent a routine medical checkup and upper gastrointestinal endoscopy revealed a duodenal neuroendocrine tumor (NET). Further studies showed the coexistence of pancreatic tumor, parathyroid hyperplasia, pituitary adenoma, and thymoma. The patient underwent duodenal endoscopic mucosal resection, distal pancreatectomy, subtotal parathyroidectomy, and thymectomy. The pathological test revealed a duodenal NET, pancreatic NET, parathyroid hyperplasia, and thymic carcinoid tumor. He was treated for MEN 1. We report this asymptomatic case of MEN 1 with a literature review.