Purpose of the study: Clear cell chondrosarcoma is a variant of bone chondrosarcoma. These unusual tumors are peculiar by their epiphyseal location in long bones, by their cytology and by their cytology and by their protracted course. Clinical, radiographical and histological features are described before therapeutic approach.
Material and methods: We report a series of thirteen cases of clear cell chondrosarcoma identified and treated between 1965 and 1995 in Cochin Hospital.
Results: Clear cell chondrosarcoma represented 5.4 per cent of the whole chondrosarcomas registered in the same period. There was a male prevalence (8 cases). Most patients were in their third decade (8 cases). Clinical course was usually of long duration ranging from three months to nine years. Roentgenographically, the lesion was often indistinguishable from chondroblastoma; this tumor involved the proximal part of the femur in 8 cases, located in the epiphysis. Histologically, cells with clear cytoplasm were always present, and areas of conventional chondrosarcoma were seen in half of cases. All patients underwent surgical treatment: "en bloc" resection was performed in 12 cases, after a curettage with bone grafting in 2 cases; a simple curettage with bone grafting was performed in one case. Two recurrences occurred: a local recurrence after a bone grafting treated by resection with good result, and another recurrence with pulmonary metastasis leading to death within 8 years.
Discussion: Clinical, radiographical and histological features are the same in our series and in the series published by Unni et al. in 1976 and by Bjornsson et al. in 1984. Treatment consists in "en bloc" resection because the lesion may recur after curettage. Rarely the tumor may metastasize. Prognosis is good with a five year survival rate similar to grade 1 chondrosarcoma (O'Neal and Ackerman classification).
Conclusion: These rare bone tumors are characterized by their good prognosis when the treatment is an "en bloc" resection.