Abstract
Objectives. Fibromatosis is a rare tumor with a prevalence of 2–4 per million per year. Its occur-rence in the thyroid is very rare and to the best of our knowledge only five cases have been reported in the literature.
Subject and Results. In this case report, we present a thirty-seven-year-old man without any significant past medical history, who presented with an anterior neck swelling and occasional cough for four months before admission. Sonographic-guided fine needle aspiration cytology studies reported a follicular neoplasm. Microscopic and immunohistochemical evaluation of the thyroidectomy specimen showed thyroid fibromatosis. The patient had no symptoms after surgery and no signs of recurrence after 2 years of follow-up.