Carcinoma Metastatic to the Thyroid Gland

Carcinomas metastasizing from other organs to the thyroid gland were considered to be rare1,2 until the 1950s3–5 when several authors began reporting a significant incidence of this entity at autopsy as well as sporadic clinically apparent cases. As more attention has been paid to this phenomenon, more has been learned about it.6–32 The incidence, clinical picture, differential diagnosis, and treatment and prognosis are discussed below.