Latent thyroid carcinoma at autopsy: a study from Oporto, Portugal.

Thirty-nine (6.5%) latent thyroid carcinomas were found in 600 thyroid glands removed at autopsy in Oporto Medical School Laboratory of Pathology. The prevalence of latent thyroid carcinomas was significantly higher in women (sex ratio 4.3:1) and in elderly people (p less than 0.005) and appeared to be independent from the existence of another malignant neoplasm. The mean thyroid weight and the concurrent thyroid pathology of patients with thyroid carcinomas were not significantly different from those of patients without them. The study of cervical lymph nodes in the first 400 autopsies did not show any significant difference concerning histologic pattern, number of germinal centers and sinus histiocytosis between patients with thyroid carcinomas and those without them. Further investigation is required to evaluate the role of host factors on the peculiar characteristics of latent thyroid carcinomas.