Chondromyxoid fibroma: report of six cases with immunohistochemical studies.

Chondromyxoid fibroma is a rare benign bone tumor of uncertain histogenesis that typically presents as an eccentric lesion in the metaphysis of a long bone of a young adult. We report S-100 positivity in six cases of myxochondroid fibroma, a finding consistent with the cartilaginous nature of the lesion and its possible relation to chondroblastoma.