The prevalence of unsuspected thyroid pathology in 300 sequential autopsies, with special reference to the incidental carcinoma.

Three-hundred whole thyroid glands were collected at autopsy from patients who had no known clinical history of thyroid disease, and who varied from 13 to 82 years of age; 200 were male and 100 female. Thyroid glands were weighed, measured, and examined after previous formalin fixation. Histologic examination was done in 16 areas from both lobes and isthmus, and divided into three levels, anterior, medial, and posterior. All areas suspected of neoplasia macroscopically were identified and studied microscopically; other areas were collected randomly for microscopic examination in the proportion of one fragment per 5 grams of tissue. In all cases both benign and malignant neoplasias were an incidental finding, seen in 6.6% of the cases and with no relation to the patient's main disease. Overall, there were malignant neoplasias in 2.33% but occult carcinoma comprised 1% of the cases. The incidence of other thyroid pathologies, all of them unrelated to the main disease of the patient, are also reported.