Hand tumour, X-ray. Coloured angiogram of a section through the swollen and distorted left hand of a 38-year-old female patient, showing a large venous haemangioma (dark, centre) and associated blood vessels (white). Haemangiomas are benign (non-cancerous) tumours arising from the endothelial cells that line blood vessels. They are characterised by an increased number of blood vessels.