Abstract
Extramedullary plasmacytoma of the thyroid gland is uncommon. We report the 18th known case in Japan.
A 76-year-old female with chronic thyroiditis was referred to our hospital because of dyspnea. The thyroid gland was wholly occupied by a large tumor and an X-ray of the neck showed a large mass in the trachea. In an emergency operation, a total thyroidectomy with a resection of the right recurrent laryngeal nerve and tracheal cartilage was performed because they had been invaded. Histopathological examination revealed a IgG/k type plasmacytoma. Multiple myeloma was not found in the bone marrow aspiration, and an X-ray of the bones in the whole body and a bone schintigram showed no abnormality. However, in spite of post operative irradiation therapy for the neck, multiple myeloma with mass lesions in the ribs and skull occurred 4 months after radiation. Chemotherapy has been performed, which has led to the disappearance of the bone lesions.
