Thyroid metastasis of endometrial carcinosarcoma associated with Graves' disease.

A 54-year-old woman who had undergone total abdominal hysterectomy and bilateral adnexial resection because of endometrial carcinosarcoma presented with thyrotoxicosis, rapidly enlarging neck mass, right cervical tenderness to the ears, palpitation, swelling and heat intolerance, 3 years after the operation. Her serum thyroid hormone levels confirmed hyperthyroidism. Triiodothyronine/thyroxine ratio was 18.