Adenomatous polyposis coli and multiple endocrine neoplasia type 2b. A pathogenetic relationship.

A young man presenting with Cushing's syndrome was found to have multiple endocrine neoplasia type 2b MEN 2b and adenomatous colonic polyposis with duodenal and gastric polyps. The entire syndrome of MEN 2b was present, including metastatic medullary carcinoma of the thyroid, a pheochromocytoma, and peripheral nerve abnormalities. The concurrence of these two inherited multiple neoplasia syndromes may reflect a common pathogenetic step in this patient.