Occult thyroid pathology in the young adult: an autopsy study of 138 patients without clinical thyroid disease.

Thyroid glands from autopsies on 138 adults, ages 20 to 40 years, with no known clinical or laboratory evidence of thyroid disease, were serially sectioned at 2 mm intervals and microscopically examined for occult thyroid disease and anatomic variations. Occult papillary carcinoma was found in 3% of the glands, along with a single case of medullary carcinoma. The prevalence of occult thyroid carcinoma in this group of young adults is significantly less than that reported in the literature in people over forty (P less than .001). The glands demonstrated a number of other morphologic changes of importance to surgical pathologists. The thyroid capsule was incomplete in 62% of the glands. Thyroid follicles were found in the capsule in 14% of cases and thyroid follicles or nodules were outside the gland in perithyroid connective tissue in 88% of cases. Thyroid follicles were identified in 7% of cases in perithyroid strap muscles attached to the pyramidal lobe. A number of other, less common anatomic variations were also seen.