A case of mediastinal goiter with hyperthyroidisms

: A 65-years-old woman admitted to the hospital in order to treat of the mediastinal tumor, but she suffered from palpitation, slight fever, sweating, uneasiness, sleeplessness and weightloss. On the physical examination, she was experiencing tachycardia, fevering (37.2 approximately 37.6 degrees C). Skin was moist but had no exophtalmos or neck tumor. Chest X-ray showed an abnormal shadow in the upper mediastinum. On chest CT, a tumor mass (9 x 5 x 4 cm) with cystic regions and scattered calcifications occupied from anterior to posterior mediastinum. The tumor compressed trachea to the left and right brachiocephalic vein and SVC to the right. Lower portion of the tumor intruded into behind of the trachea. Lymph node swelling of mediastinum was also detected. Results of general laboratory examination were within normal limits. Thyroid function test revealed hyperthyroidism; T3U 58%, free T3 24.4 pg/ml, free T4 6.0 ng/dl and thyroglobulin 967 mg/dl, but TSH was < 0.01 microIU/ml. After daily administration of methimazole (300 mg/day) for 4 weeks, thyroid function became to normal level and symptoms of hyperthyroidism was disappeared. The tumor was completely extirpated with right hemithyroidectomy and lymph node dissection under neck colla incision and median sternotomy. Pathological finding of the tumor showed follicular-fetal adenoma of thyroid with hyaloid degeneration and cystic change. There was no finding suspected of Graves' disease. She is well without any complications for 8 months after operation. Some discussion of the literature was mentioned.