Multiple endocrine neoplasia type 2b in twins.

The syndrome of multiple endocrine neoplasia (MEN or MEA) type 2b is characterized by the association of medullary carcinoma of the thyroid, phaeochromocytoma, ganglioneuromatosis and Marfan-like features. Though this disorder usually shows a familial distribution, it may also appear spontaneously as the result of a genetic mutation. This paper describes the second case of MEA type 2 in twins, and appears to be the first description in twins of the association of medullary carcinoma of the thyroid, Marfan-like features and multiple neuromas.