Blood vessel tumour, coloured ultrasound scan. The tumour (orange) is in the liver. It is an angioma, a benign tumour formed from a clump of distended blood vessels. It may cause internal bleeding if a blood vessel bursts. Surgical treatment can reduce blood flow to the area. However, an important role of the liver is to detoxify the blood. The angioma has developed as part of Waldenstrom's disease or macroglobulinaemia, a blood disorder where excess antibodies called macroglobulins (IgM) thicken the blood. It is incurable, though filtering the blood helps relieve symptoms. It is a rare disease, and mostly affects older men. This case is complicated by cirrhosis of the liver.