Malignant Transformation of Multiple Hand Enchondromas Secondary to Ollier Disease: A Case Report.

Enchondromatosis secondary to Ollier disease (OD) is rare, with secondary chondrosarcomas (CS) accounting for only 1% of malignant osseous tumours. This is one of only two reports documenting four enchondromas of different bones of the same hand developing malignant transformation, with long-term follow-up. This is a 72-year-old female with histologically proven CS from multiple enchondromas of the index finger metacarpal and proximal phalanx, and middle finger proximal and middle phalanges. Six years following curettage and bone grafting, she showed no recurrence or metastases from CS. While CS of the hand behaves aggressively, they rarely metastasise and show good 5-year survival rates. Due to good prognosis, function-sparing surgical options are acceptable over amputation, accompanied by close surveillance. Level of Evidence: Level V (Therapeutic).