[Fibrous dysplasia associated with intramuscular myxoma].

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 underlying mechanism.

CASE REPORT

A 45 years male consulted for a large painful swelling of the right gluteal muscle. The CT scan revealed the soft tissue tumor associated with a bone cyst of the right pelvic bone. The mass was removed at operation and tumoral bone tissue was curetted, there were no evidence of tissue continuity between the two lesions. The histological diagnosis was intra muscular myxoma and fibrous dysplasia.

DISCUSSION

Intra muscular myxoma associated to fibrous dysplasia of bone is a rare syndrome described by Mazabraud in 1957. A review of the literature until 1995 reveals that only 17 cases of this syndrome have been reported. Intra muscular myxoma is a rare benign soft tissue tumour arising from fibroblast. Fibrous dysplasia is a hamartomatous bony disorder, which appears in mono or polyostotic forms, with or without extraskeletal manifestation.

CONCLUSION

It was not possible to demonstrate a clear correlation between the two lesions. The authors suggest that myxoma result from bone mechanical disorders.