ANAPLASTIC TRANSFORMATION OF A PAPILLARY CARCINOMA OF THE THYROID IN A PATIENT WITH GRAVES-DISEASE WITH VARIED ACTIVITY OF THYROTROPIN RECEPTOR ANTIBODIES

We describe a 75-year-old man who had had a lump in his neck for about 15 years. At his first visit to our hospital, poorly differentiated p apillary carcinoma of the thyroid was diagnosed by means of aspiration cytology; xrays revealed the presence of lung metastases. He was thyr otoxic with positive thyroid stimulating antibody (TSAb). He was reluc tant to undergo surgery. In an early stage of the treatment for Graves ' disease, he became hypothyroid with decreased TSAb activity and stro ngly positive thyroid stimulation blocking antibody (TSBAb), and rapid growth of the thyroid carcinoma with anaplastic transformation was ob served. The increase in the size of the transformed thyroid carcinoma was shown to be exponential by ultrasonography. This is a rare case in which anaplastic transformation of the thyroid papillary carcinoma be came apparent during treatment of Graves' disease with varied activity of thyrotropin receptor antibodies.