The natural history of a hepatic angiosarcoma that was difficult to differentiate from cavernous hemangioma.

A 69-year old man came to our hospital complaining of abdominal pain. Contrast-enhanced computed tomography (CT) showed a 65-mm ruptured mass in Couinaud segment 5 of the liver. The mass was treated with emergent transcatheter arterial embolization (TAE), followed by partial hepatectomy. Microscopically, the mass was determined to be an angiosarcoma. Six months previously, enhanced CT had shown a 15-mm mass diagnosed as a cavernous hemangioma in the same region of the liver. Even when the enhancement pattern of a small hepatic mass resembles that of hemangioma, the mass should be reassessed within several months to exclude a diagnosis of hepatic angiosarcoma.