Chondrosarcoma of the first metatarsal--primary or secondary to enchondroma?

Enchondromas are said to be extremely rare precursors of secondary chondrosarcomas. Peripheral enchondromas of the hand and foot may be considered as benign, even when the histomorphological study reveals pleomorphic features with atypical nuclei. Our case deals with a 56 year old woman who had an enchondroma of the first metatarsal. Its distinct histopathological signs of focal malignant transformation were only seen in later review. Nine months after curettage and autologous bone-grafting a chondrosarcoma was diagnosed. The enbloc-resection of the medial foot provided adequate surgical treatment of the chondrosarcoma.