Chondrosarcoma in hereditary multiple exostosis and Ollier's disease. A clinical analysis of 29 cases and literature review

Purpose of the study Several studies have demonstrated better prognosis of chondrosarcomas arisi ng in hereditary multiple exostosis or Oilier's disease. The aim of this st udy was to evaluate their clinical, radiological and histological features and compare their prognosis with other chondrosarcomas. Material and methods We reviewed twenty nine secondary chondrosarcomas among seventeen patients with osteochondroma (group A), and eight with Oilier's disease (group B). T hese tumors represented 12 p. 100 of all chondrosarcomas treated between 19 50 and 1994 in Cochin Hospital. Two group B patients successively developpe d three multicentric chondrosarcomas. Twenty six resections (eight intra an d eighteen extralesional), two disarticulations and one amputation were per formed as primary treatment. The average follow-up of the study was 10.5 ye ars. The results were evaluated by means of survival curves. The significan ce of the difference between the curves was determinated by the log-rank te st. Results The mean age of malignant change was 36 years old. The most frequent tumora l site was the inominate bone for group A and the femur for group B. In thr ee cases, radiographs showed no malignant features. Ail chondrosarcomas wer e classified as grade 1 or 2. The ten-year survival rate was 82 p. 100 with no significant difference between the two groups. The survival rates were significantly different after carcinologic surgery (extralesional resection or amputation) and contaminated surgery (intralesional resection), with 5 and 88 p. 100 of local recurrences respectively. Discussion and conclusion These secondary chondrosarcomas represent about 10 p. 100 of all chondrosar comas. They appear 15 years earlier. According to O'Neal and Ackerman class ification, most of the tumors are well-differenciated (60 p. 100 grade 1, 3 9 p. 100 grade II and 1 p. 100 grade III). Carcinologic surgery is generall y curative. Ten-year survival rate is 94 p. 100. With equivalent grade and surgery, their prognosis is better as compared to primary chondrosarcomas.