Histologic changes in previously irradiated thyroid glands.

Thyroid tissue from 90 patients with a history of therapeutic irradiation to the head and neck in childhood and adolescence was examined microscopically. In addition to the well-known observation that these individuals have an increased incidence of primary thyroid carcinoma, it was also demonstrated that they have an increased incidence of benign histologic changes. These changes represent a spectrum from nonspecific hyperplastic lesions to benign neoplasia and thyroiditis.