Calcified thrombus of the inferior vena cava in transposition of the great vessels.

Calcified thrombus of the inferior vena cava (IVC) in children is an entity usually not associated with significant complications. The possibility of pulmonary embolism from the soft thrombus, however, has been suggested but never reported. We give an account of a child with transposition of the great vessels who suffered embolization from a calcified thrombus in the IVC that entered the systemic circulation.