[Ectopic retroperitoneal thyroid gland]. / Ectopia tiroidea retroperitoneal.

The presence of subdiaphragmatic thyroid tissue is a very rare finding. We reviewed the literature and found only 15 published cases. The most appropriate management of this entity has not been established, but surgical removal is common to exclude malignancy. We present the case of a 76-year-old woman with an ectopic mesenteric thyroid gland forming a retroperitoneal mass that was surgically removed. Outcome was favorable.