Testicular tumour. Coloured 3-D ultrasound scan of a patient with an haemangioma (lower centre) on his testicle. Haemangiomas are benign tumours that are caused by abnormal growth of the blood vessels. Most haemangioma growths do not produce symptoms, although a few may become painful, or rupture and cause severe bleeding. In these cases surgery would be required. Ultrasound is a diagnostic technique that sends high frequency sound waves into the body via a transducer. The returning echoes are recorded and used to build an image of an internal structure. 3-D ultrasound uses computer technology to return more detailed images than conventional 2-D scans.