Case report 747: Leiomyosarcoma of great saphenous vein.

Vena caval leiomyosarcomas are rare tumors; noncaval leiomyosarcomas are even less common and are rarely diagnosed preoperatively. We present a case of leiomyosarcoma of the great saphenous vein that was diagnosed by MRI based on its appearance and location. The presence of an intraluminal tumor in a vein on MRI should suggest the diagnosis of leiomyosarcoma of the vein, allowing definitive operative excision. With widespread use of MRI for indeterminate soft-tissue masses, we anticipate presurgical diagnosis of venous leiomyosarcoma will be made with increasing certainty and frequency.