[Chondromyxoid fibroma of bone: a rare benign bone tumor in children].

Chondromyxoid fibroma is a rare benign tumor that is typically found in the metaphyseal ends of long tubular bones, such as the tibia. The radiographic appearances are those of a single, lytic lesion with lobulated margins, septations, cortical expansion and a sclerotic rim. The classic histological feature of a chondromyxoid fibroma is stellate or spindle-shaped cells arranged in lobules in a myxoid or chondroid background. Two cases are presented here: 8, and 12-year-old patients, both with lesions in the proximal tibia. The first case showed an unusual feature: it was diaphyseal chondromyxoid fibroma. In the second case, the lesion was metaphyso-diaphyseal. The differential diagnosis includes chondroblastoma, myxoma, aneurysmal cyst as well as chondrosarcoma. A surgical conservative treatment with complete excision is recommended even in case of recurrence.