Vascular tumors simulating occlusive disease

Two cases of vascular tumors of large vessels with intraluminal growth simu lating venous thrombosis and arterial occlusive disease are reported. One w as a borderline malignant epithelioid hemangioendothelioma of the femoral v ein and the other a malignant epithelioid angiosarcoma of the carotid arter y. Immunohistochemical studies permitted to classify the tumors. Treatment consisted in surgical resection. No recurrence and no metastasis are noted at 24 months. Uncertainty regarding biological behaviour of vascular tumors and treatment persists.