[Familial nonmedullary thyroid cancer].

Familial occurrence of nonmedullary thyroid carcinoma is rare but this has been increasingly recognized over the recent years. Epidemiological studies showed that relatives of thyroid cancer cases were at increased risk of the same site. Surveying published familial cases, there were two groups of familial thyroid carcinoma; groups related to other familial diseases(familial adenomatous polyposis FAP, Gardner's syndrome, Cowden's disease) and another independent of accompanying disease. Familial thyroid carcinomas independent of accompanying disease were reported aggressive features and several authors recommended aggressive treatments. Genetic bases has not been clearly elucidated identification of genetic defects should undoubtedly aid an understanding of pathogenesis of sporadic cases.