CHONDROMYXOID FIBROMA OF THE FOOT AND ANKLE

Abstract

Ten cases of histologically proven chondromyxoid fibroma (CMF) of the Foot and Ankle with a mean follow-up of 6.1 years were reviewed. The mean age was 19 years (12.8 for skeletally immature and 25.2 for remaining skeletally mature patients). There were 6 males and 4 females. There were 5 phalangeal (3-proximal, 1-middle and 1-terminal phalanx), 3 metatarsal, 1 tarsal affecting body of os calcis and one case of distal tibial involvement. The mean delay in presentation was 16.7 months. The common modes of presentation were pain only (n=4), painful lump (n=4) and painless lump (n=2). Typical x-ray finding was an expansile, lobulated, cystic metaphyeal lesion. Cortical erosion was documented in 50% patients. Histology confirmed by several pathologists due to difficulty in diagnosis. There were two atypical CMF. In four cases, curettage alone was carried out, while 5 underwent curettage along with autogenous bone grafting. One case of distal phalangeal CMF had primary toe amputation. Postoperatively, calcaneal CMF had infection (treated with wound debridement and re-curettage). Two cases observed recurrences after 9 and 16 months from their initial operation. Both of them were male, had preliminary proximal phalangeal CMF, showed to have cortical erosion and were treated with curettage only. Re-curettage was done for one, while toe amputation through the metatarsal neck was performed for another recurrence. Foot phalangeal CMF which were initially treated with curettage only should be kept under close follow-up as we observed 20% recurrence rate within two year period. Cases with cortical erosion should be supplemented with autogenous bone grafting.