Leiomyosarcoma of the inferior vena cava

Tumors originating in the walls of large veins represent a very rare lesion, and only 29 cases have been reported in which such an origin could be definitely demonstrated. 1 Twenty-six of these were thought to be derived from smooth-muscle elements, the other 3 being classified as endothelioma, enchondroma, and osteogenic sarcoma. Of the smooth-muscle tumors, 15 were regarded as malignant and the other 11 as benign. These lesions have occurred in veins of the extremities and chest as well as in the abdomen, but over half of the sarcomas originated in the inferior vena cava. There are at present 8 cases of leiomyosarcoma and 1 case of leiomyoma which have been reported as developing from the muscularis of the wall of the inferior vena cava. In view of the rarity of the lesion we felt it advisable to document another case in which an unequivocal leiomyosarcoma was encountered arising