Angiosarcoma of kidney, light micrograph. Angiosarcoma is a rare, highly aggressive tumour that makes up less than 1% of all sarcomas. They show variable degrees of blood vessel formation and range from well-differentiated tumours resembling haemangiomas to highly anaplastic solid tumour that may be mistaken for poorly-differentiated carcinomas or sarcomas. The most common location is skin (scalp, face, forehead, and neck), followed by parenchymal organs (breast, heart, liver, spleen, and bone) and deep soft tissues. The peak incidence is seen in the 7th decade. Primary angiosarcoma of the kidney is a rare tumour. It is most commonly seen in the 6th and 7th decades of life (mean age of 61 years) with a male predilection. The aetiology of primary angiosarcoma of kidney is not known; however, like liver, some case have been linked to exposure to carcinogens like thorotrast, arsenic, and polyvinyl chloride. This image of renal angiosarcoma shows anastomosing vascular channels lined by