MEN1 and primary hyperparathyroidism: The clinical presentation of MEN1 varies considerably as MEN1-related tumors may manifest due to local tumor growth, tumor burden, or metastases as well as hormonal hypersecretion, which can lead to development of specific clinical phenotypes associated with primary hyperparathyroidism, prolactinomas, acromegaly, Cushing disease, gastrinomas, and insulinomas (1).