Anatomy and radiology of a bone island.

Anatomoradiological study, on an amputation specimen for osteosarcoma from a 13 year old girl, of a bone island in the distal femoral epiphysis. It consists of a mature bone core caused by localized remodeling of the spongeous trabeculae, old but still slightly active, clearly different from a bone infarct, a tumoral or infectious process. Discussed the interest of a precise radiological study for making the diagnosis (particularly xerography), the risks of error involved in scintigraphy and the utility of a block excision if a biopsy is performed.