Gorham's disease. Coloured 3D (left) and 2D (right) computed tomography (CT) scans of the skull of a 47-year-old patient, showing damage (centre) caused by osteolysis (bone resorption and replacement) characteristic of Gorham's disease. Gorham's disease, or vanishing bone disease, is a very rare skeletal condition of uncertain origin. It is characterised by the uncontrolled proliferation of distended, thin-walled vascular or lymphatic channels within bone, which leads to resorption and replacement of bone with angiomas (benign tumours) and/or fibrosis (formation of excess fibrous connective tissue).