OSTEOCLASTOMA

also called giant-cell tumour of bone a bone tumour found predominantly in the knee region, but also occurring in the wrist, hand, foot, arm, and pelvis. The giant cells (large, often multinucleated cells) found in these tumours resemble osteoclasts, for which the tumour is inappropriately named. Usually seen in young adults between the ages of 20 and 40, this relatively uncommon, painful tumour is considered potentially malignant. Most tumours are benign at the outset and are removed by curettage (scraping). Unfortunately, about 50 percent of the tumours removed in this way recur, of which a small percentage spread to other parts of the body (metastasize). This has prompted some physicians to recommend more aggressive treatment, such as complete excision or amputation.