Multiple endocrine neoplasia type 1
MEN1 is typically not diagnosed until patients are in their 40s. The hallmark finding is hypercalcemia secondary to hyperparathyroidism. However, patients also frequently present with signs and symptoms secondary to a pancreatic endocrine tumor and may have mildly elevated serum calcium. Cutaneous angiofibromas and collagenomas can be helpful diagnostic clues within the setting of hypercalcemia or pancreatic endocrine tumors. Some patients, however, have few skin findings at diagnosis.
MEN1 is also strongly associated with Zollinger-Ellison syndrome (ZES). In patients with both disorders, the diagnosis of ZES can precede the diagnosis of hyperparathyroidism and the initial diagnosis of MEN1 by many years, sometimes decades. Malignant gastrinomas causing ZES are reported in 20% to 70% of patients with MEN1. Thymic carcinoid tumors can be aggressive, and patients can have a number of different neuroendocrine tumors. Melanomas are also associated with MEN1. Menstrual irregularity and infertility can occur secondary to a prolactinoma.
Related topics: MEN2a, MEN2b
E31.21 – Multiple endocrine neoplasia [MEN] type I
30664006 – Multiple endocrine neoplasia, type 1
Differential Diagnosis & Pitfalls