INTRAMUSCULAR MYXOMA ASSOCIATED TO FIBROU S DYSPLASIA

Purpose of the study The association of fibrous dysplasia and of soft tissue myxoma is rare. The authors report a new case and discuss the u nderlying mechanism. Case report A 45 years male consulted for a large painfull swelling of the right gluteal muscle. The CT scan revealed t he soft tissue tumor associated with a bone cyst of the right pelvic b one. The mass was removed at operation and tumoral bone tissu was cure tted, there were no evidence of tissue continuity between the two lesi ons. The histological diagnosis was intra muscular myxoma and fibrous dysplasia. Discussion Intra muscular myxoma associated to fibrous dysp lasia of bone is a rare syndrome described by Mazabraud in 1957. A rev iew of the literature until 1995 reveals that only 17 cases of this sy ndrome have been reported. Intra muscular myxoma is a rare benign soft tissue tumour arising from fibroblast. Fibrous dysplasia is a hamarto matous bony disorder, which appears in mono or polyostotic forms, with or without extraskeletal manifestation. Conclusion It was not possibl e to demonstrate a clear correlation between the two lesions. The auth ors suggest that myxoma result from bone mechanical disorders.