Parosteal osteosarcoma of the fourth metatarsal bone

The authors present a case of a parosteal osteosarcoma of the fourth metatarsal in a 19-year-old male. This location has never been previously reported. The periosteal new bone formation without bone destruction must be differentiated from foreign body reaction and stress fractures. En bloc resection of the fourth and fifth rays was done. There has been no evidence of recurrence to date, 1 year and 10 months following the surgery. There has been an excellent functional result.