[Familial adenomatous polyposis and thyroid cancer].

Familial adenomatous polyposis may exhibit extracolonic tumors which include thyroid carcinoma. It has been recently suggested that thyroid carcinomas associated with familial adenomatous polyposis show distinct histologic features different from sporadic follicular or papillary thyroid carcinomas. We report a case of thyroid carcinoma in a young girl affected by familial adenomatous polyposis, whose thyroid tumor exhibited some of these features. This finding confirms the peculiar histologic phenotype of the thyroid carcinomas associated with familial adenomatous polyposis. Alterations of the APC gene responsible for familial adenomatous polyposis may play a role in the development of these thyroid cancers.