A review of literature of a functional, congenital intrathoracic kidney.

Introduction: The rarest form of renal ectopia, the thoracic kidney, has been documented in only about 200 cases worldwide. There are four recognized causes of congenital thoracic renal ectopia: renal ectopia with an intact diaphragm, diaphragmatic eventration, diaphragmatic hernia, and traumatic diaphragmatic rupture. This condition often presents as an incidental finding in asymptomatic patients.