Multiple endocrine neoplasia.

The multiple endocrine neoplasia (MEN) syndromes are well-defined disorders characterized by familial inheritance of specific endocrine tumors. The parathyroid, endocrine, pancreas, and pituitary tumors of MEN-1 are described by frequency and symptomatology. The effectiveness of surgery, symptomatic therapy, and panendocrine suppression by the somatostatin congener octreotide are discussed. Evidence indicates that the MEN-1 gene is located on chromosome 11 and tightly linked markers can help identify family members at risk for inheriting the gene. In MEN-2, the effectiveness of biochemical screening for thyroidal C-cell neoplasms and early thyroidectomy are described. New imaging techniques have been developed to identify medullary thyroid carcinoma and pheochromocytoma in MEN-2. Genetic analysis has identified markers on chromosome 10 closely linked to the MEN-2a gene, allowing better identification of family members likely to develop the syndrome.