Radioiodine treated hyperthyroidism and thyroid carcinoma.

External irradiation of the head and neck has been shown to increase the incidence of thyroid carcinoma. Fourteen cases have also been reported of thyroid cancer developing in individuals treated with radioiodine for hyperthyroidism. Another patient's case is reported here to emphasize the possible role of I131 on the genesis of thyroid malignancy and the importance of surgery in the treatment of hyperthyroidism.