Primary leiomyosarcoma of the thyroid gland.

Primary leiomyosarcoma of the thyroid gland is extremely rare, and to the best of our knowledge only five well-documented cases have been reported in the world literature. We herein report a 58-year-old female patient with primary leiomyosarcoma of the thyroid who was successfully treated by total thyroidectomy with a modified neck dissection. Immunohistochemically, the tumor cells showed positive reactivity to alpha-smooth muscle actin and vimentin. Radical surgery was thus considered to be essential in the treatment of this rare but rather aggressive malignancy.