ABSTRACT
The multiple endocrine neoplasias (MEN) are inherited diseases characterized by the occurrence of hormonesecreting/hormone producing tumors in two or more endocrine glands in an individual patient and/or in the patient and one or more family members. Although they are relatively rare, their importance is due to their risk ofmalignancies, which can be reduced by early diagnosis and treatment, especially among family members. There are two types of MEN syndromes: type-1 and type-2. Multiple endocrine neoplasias type-2 (MEN-2) has been further subcategorized into two clinical forms called MEN-2a and MEN-2b (formerly MEN3) with distinct patterns of tissue involvement (Table 1). MEN-1 and MEN-2 share certain characteristics: both of these syndromes have dominant patterns of inheritance. They are hormone producing endocrine tumors, which are often benign in nature but have a potential for malignancy. They occur relatively early in life which allows for the screening of asymptomatic family members at risk.
Multiple endocrine neoplasias-1 (MEN-1) was first described more than 50 years ago as Wermer’s syndrome (1). MEN-1 is a dominant autosomal disorder characterized by tumors of the parathyroid glands, anterior pituitary (AP), and pancreatic islets. Foregut carcinoid tumors are less commonwhile nonendocrine tumors such as lipomas, facial angio-fibromas, and skin collagenomas are relatively frequent. Endocrine and nonendocrine features of MEN-1 and their relative frequencies are summarized in Table 2 (2,3). The prevalence ofMEN-1 as estimated by autopsy studies approximates 2.5:1000. However, 1% to 18% of patients with primary hyperparathyroidism have been variously
