Solitary fibrous tumor of the thyroid gland.

Solitary fibrous tumor (SFT) is a rare spindle-cell neoplasm more commonly involving the pleura, but recognized also in other tissues. Nineteen patients with SFT arising from the thyroid gland have been reported in the literature. The present report reviews these cases and discusses epidemiology, etio-pathogenesis, clinical-pathologic characteristics, differential diagnosis, therapy, and prognosis of thyroid SFT.