Canine splenic hemangiosarcoma with abdominal dissemination.

Disseminated hemangiosarcoma was encountered in a 12-year-old female Maltese dog. Tumor tissues were dispersed on the serosal surface of the liver, kidney, digestive tract, omentum and diaphragm. Metastatic lesions were not observed in the parenchyma of the lung and heart. The spleen was enlarged with rupture at the anterior region of the hilus. The disseminated protruding tumor masses could be easily peeled off from the organ surfaces. The tumor cells were round or spindle in shape, with hyperchromatic nuclei containing prominent nucleoli. Various-sized vascular spaces containing erythrocytes and serum could be identified in this tumor. This case was diagnosed as hemangiosarcoma originating from the spleen with abdominal dissemination.