Rarest of the bone tumors: Chondromyxoid fibroma

Abstract

Chondromyxoid fibromas are extremely rare benign cartilaginous neoplasms with incidence <1% of all bone tumours. Most commonly seen before 30 years of age (75%) with slight male predilection. Most common location is proximal tibia (25%). Malignant degeneration is rare and high recurrence with curettage alone (80%) and four times lesser with curettage and bone grafting (20%). Case report: A 22 year old male presented with pain in the left knee since 1 year and swelling in the left leg since 6 months with no restriction of movements. Patient was investigated and lesion was confirmed to be chondromyxoid fibroma. Intraoperatively, mass was greyish with variable consistency. Curettage was done and the cavity was filled with cortico-cancellous bone graft. Histopathological examination confirmed it to be chondromyxoid fibroma and negative for malignancy. The intra and post-operative periods were uneventful. Limb was supported with long posterior slab post-operatively. Conclusion: Chondromyxoid fibromas are rarest benign cartilaginous neoplasms. Hence, it is important to consider differentials. Core needle biopsy of lesion is helpful before planning the procedure as the treatment options change significantly. Counselling for recurrence and malignant transformation to sarcomas is advisable.