Thyroid carcinoma.

Pathological and clinical characteristics of thyroid carcinoma are reported. In 379 routine consecutive autopsies in which carcinoma was not suspected, serial sections of thyroid gland were histologically examined. Latent thyroid carcinoma was detected in 15.7% of the glands. Papillary adenocarcinoma comprised 76.3%, follicular adenocarcinoma 22.0% and trabecular carcinoma 1.7% of the cases. Sclerosing carcinoma was seen in 32 cases. The long diameter of 90% of these tumors was less than 5 mm. Whether or not thyroid carcinoma persists as such a small carcinomatous lesion indefinitely was studied along with its clinical significance. Carcinomatous lesions complicating hyperthyroidism were always less than 1 cm. About 70% were less than 5 mm long. Since proliferation of some thyroid carcinomas was inhibited by TSH suppression therapy, growth and proliferation of carcinoma in the presence of excessive thyroid hormone or hyperthyroidism is probably already inhibited.