Primary osteosarcoma of toe phalanx: first documented case. Review of osteosarcoma of short tubular bones.

A case of a sclerosing variant of osteosarcoma of a toe phalanx is reported in a 28-year-old man. This represents the first reported case of osteosarcoma of any kind at this site. This is based on a review of 4,214 cases of conventional osteosarcoma. The reason for the extraordinary rarity in toe or hand phalanges is unknown although osteosarcoma is the second most common primary tumor of bone. Since the neoplasm had minimal signs of cytologic anaplasia, it was originally mistaken for and treated as an osteoid osteoma. The lesion recurred and extended into soft tissues. Reevaluation revealed the tumor to be an osteosarcoma, sclerosing variant with "normalization" of nuclei. The lesions that this tumor should be distinguished from are osteoid osteoma and osteoblastoma.