Clear Cell Chondrosarcoma-Oncological Outcomes in an Asian Cohort

Clear cell chondrosarcoma is a rare subtype of chondrosarcoma, included in the category of low-grade (grade 1) sarcomas of the bone. We evaluated the results of treatment of these rare tumours at our institute and documented their outcomes in a hitherto unreported ethnic (Asian) cohort. Of the 480 extremity and pelvic chondrosarcomas diagnosed between January 2006 and December 2017 at our institute, 12 (2.5%) were clear cell chondrosarcoma. There were 11 male patients and one female patient. The mean age was 35 years (range 24-51 years). Mean duration of symptoms was 6 months and all cases were in the long bones; 8 cases in the femur, 2 in the humerus, and 1 each in the tibia and fibula. All cases were non metastatic at presentation Three patients were excluded from final analysis as they did not seek treatment at our hospital after initial presentation. Seven of nine cases had elevated alkaline phosphatase levels (mean value of 342 and range of 94-1353). Eight cases underwent wide excision while one case who had curettage elsewhere and presented to us with no evidence of residual disease was managed with watchful observation. None of the patients received adjuvant chemotherapy or radiotherapy. There were no local or distant recurrences at a median follow-up of 73 months (range 43-244 months). Seven of nine cases had elevated alkaline phosphatase levels (mean value of 342 and range of 94-1353). Eight patients were alive and disease free at last follow-up while one had died due to an unrelated cause at 76 months after index surgery. Clear cell chondrosarcomas comprised only 2.5% (12 of 480) of all chondrosarcomas in our study. Elevated serum alkaline phosphatase levels may serve as a surrogate marker to help in diagnosis. Wide excision in clear cell chondrosarcomas is recommended and provides excellent oncological outcomes.