Thyroid nodules after high-dose external radiotherapy. Fine-needle aspiration cytology in diagnosis and management.

From 1974 to 1980, we studied six patients, five treated for Hodgkin's disease and one for a hemangioma, in whom thyroid nodules developed after high-dose (2,500 to 4,000 rad) thyroid radiation. Fine-needle aspiration cytology of the thyroid in five cases showed moderate to severe cellular atypia in four (three of whom had elevated serum thyrotropin levels) and mild atypia in one (who was overtly hypothyroid). In the four with marked atypia, surgical pathology disclosed Hashimoto's thyroiditis in one, diffuse hyperplasia and epithelial atypia in two, and a sclerosing papillary carcinoma in one. Among five patients who had total thyroidectomy, three had carcinoma (microscopic papillary, papillary-follicular, or sclerosing papillary) in addition to one or more follicular adenomas or colloid nodules. Thyroid nodules and neoplasia may be more common than previously appreciated in patients exposed to high-dose radiation.