HISTOLOGIC LESIONS IN THE THYROID GLANDS OF PATIENTS RECEIVING RADIOIODINE FOR HYPERTHYROIDISM*†

Abstract

HISTOPATHOLOGIC lesions in hyperplastic thyroid glands of patients treated with radioiodine lack detailed descriptions. This study was concerned with 23 hyperthyroid patients who had hyperplastic or nodular thyroid glands irradiated with I131 and examined later histologically. The purpose of this report is to describe and illustrate a variety of alterations observed in these glands, to discuss their pathogenesis, and to relate them to the interrupted course of hyperthyroidism. Our studies have indicated that amelioration of hyperthyroidism may occur following irradiation of the thyroid gland with I131, usually in the absence of the classic structural changes generally associated with injury from radiation. Twenty-one patients received radioiodine (I131) therapeutically. Two patients (Cases 10 and 19) received only test doses of I131 (Table 1). Nine patients received I131 as the sole therapeutic agent; the remainder had, in addition, either Lugol's solution, thiouraciltype drugs, or both. None of these drugs had been administered within one month of commencement of therapy with I131.