Thyroid cancer after irradiation.

Nine patients with thyroid cancer who had received irradiation on the thyroid region (four for breast cancer with deep x-ray or Co60, one for a skin lesion with deep x-ray and four for hyperthyroidism with I131) have been discussed. These cases might be within the range of statistical coicidence, but the potential carcinogenic effect of irradiation could not be ruled out completely. The need for detailed examination of the thyroid gland before and for many years after irradiation and early removal of thyroid gland nodules which develop after I131 treatment are emphasized.