Occult thyroid carcinoma at autopsy in Malmö, Sweden.

Thorough examination of complete thyroid glands from 500 consecutive autopsies in a Swedish population revealed 43 primary thyroid carcinomas (8.6%). Thirty-two were papillary, seven follicular, and four medullary. All but three follicular carcinomas were less than 1 cm and clinically unsuspected. The prevalence of occult papillary carcinoma did not differ significantly between men and women and there was no definite increase in frequency with age in the age groups studied (40-90 years).