A case of a reare live tumor is described in a 49-year-old woman, presenting the structure of a hemangio-endotheliosarcoma, according to FOOTE's nomenclature. The liver, 1700 gr. in weight, was the seat of numerous formations of different sizes, its appearance being comparable to that of a cavernous hemangioma (ill. 1) sending forth a small number of metastases to the spleen (ill. 2). On microscopical examination, the AA. coud recognize the histological structure of cavernous hemangioma associated with atypic proliferation of vascular endothelium with the propriety of reproducing new and imperfect vascular spaces (ill. 3-4-5-6-). In the spleen, although on a smaller extension, the structure is similar to that observed in the liver (ill. 7). On analytical examination of different hypotheses concerning the histogenesis of the tumor, one may admit its origination at the expense of anaplastic transformation of the cavernous hemangioma of the liver.