multiple endocrine neoplasia syndromes, designated as type 1 (Wermer's syndrome), type 2A (Sipple's syndrome), and type 2B. These involve tumour formation or hyperplasia in various combinations of endocrine glands. Type 1 involves the parathyroid, pituitary, and pancreas, whereas type 2A involves the thyroid medullary cells, the adrenal medulla (phaeochromocytoma), and the parathyroids. Type 2B is similar to 2A, but patients tend to resemble people with Marfan's syndrome and have multiple neuroma on their mucous membranes.
Medical dictionary. 2011.