OrthoNet

Chondromyxoid Fibroma

- rare benign cartilage tumor occurring in 2nd & 3rd decades
- usu in long bones (esp proximal tibia)

Signs & Symptoms:
- pain localized to region of tumor
- tenderness, pain on motion of the affected joint, localized swelling, palpable mass

Xrays:
- eccentric, lytic lesions located in metaphysis
- lobular lesion sharply demarcated from normal surrounding bone by scalloped slightly sclerotic rim
- overlying cortex thinned & expanded

Histology:
- poorly lobulated containing spindled & stellate cells with abundant myxoid matrix
- matrix calcification may be present
- multinucleated giant cells & round cells resembling chondroblasts in fibrous tissue btw lobules
- cystic spaces resembling aneurismal bone cysts may be seen

Treatment:
- intralesional curettage & bone grafting à 85-90% cure rate
- occasionally locally aggressive requiring wider local resection