Morphologic changes in the thyroid following low-dose childhood radiation.

Surgically resected thyroid specimens were obtained from 18 patients who had received low-dose head and neck radiation during infancy or early childhood. Twelve of the eighteen patients had thyroid carcinoma, with six having lymph node metastasis. In eight the malignancy was not found in the nodule that prompted the surgery but was discovered only after thorough examination of the entire specimen. Our patients showed a number of other histologic changes, not previously emphasized in the literature. They uniformly had marked multinodularity, extensive interstitial fibrosis, and in some cases lymphocytic thyroiditis.