Thyroid carcinoma and radiation. A Chicago endemic.

Radiation-associated thyroid carcinomas continue to occur with alarming frequency. Among 50 patients with thyroid carcinoma seen over the past four years, 20 had received prior neck x-ray treatment. These patients developed tumors an average of 20 years after x-ray exposure, and were nearly all under 35 years of age. Clinical findings were similar to those of the nonexposed carcinoma patients, but the tumors were less invasive and never undifferentiated. One patient in the x-ray group succumbed to the illness. Two thirds of our patients who have a history of known x-ray exposure and who showed clinical thyroid abnormalities had cancer. All patients who received significant x-ray exposure during childhood or adolescence should be examined for thyroid abnormalities, which may develop two or more decades after exposure.