Malignant hemangiosarcoma in a renal allograft: diagnostic difficulties and clinical course after nephrectomy and immunostimulation.

Hemangiosarcomas are rare tumors of endothelial cell origin. To date, only 20 cases of hemangiosarcoma have been described after renal transplantation, occurring mostly in the skin or in a dialysis fistula. We report a primary metastasizing hemangiosarcoma arising from a renal allograft.