[Vena cava occlusion-syndrom by leiomyosarcoma. Two case reports (author's transl)].

Two cases of occlusion of the inferior vena cava by leiomyosarcoma are reported. This localisation is extremely rare for mesenchymal tumors. The neoplasm originated from the wall of the vena cava, expanded forward into the lumen of the vessel, in one case up to the right atrium. Collateral circulation, anasarca edema and varices develop by this occlusionsyndrome. The fatal outcome of the disease is usually determined by right heart failure and not by metastases directly. In most cases diagnosis is made by autopsy. In cavography the differential diagnosis of thrombosis might include the rare possibility of leiomyosarcoma of the caval vein. Only early diagnosis makes succesful surgical therapy possible.