Malignant epithelioid angiosarcoma of the external iliac vein presenting as venous thrombosis.

A case is reported of a 28-year-old female who initially presented with a right iliac deep venous thrombosis of unclear etiology. A stenosis in the iliac vein was seen, but no intrinsic or extrinsic mass was noted on multiple imaging studies. The patient presented 2 years later with right hydronephrosis, and at that time a right pelvic mass was discovered. Resection was performed with concomitant reconstruction of the right iliac arterial system, and pathology revealed a malignant epithelioid angiosarcoma.