Extraskeletal myxoid chondrosarcoma of the chest wall masquerading as a breast tumor. A case report.

Background: Extraskeletal myxoid chondrosarcoma is a rare tumor that usually occurs in the soft tissues of extremities. Cytologic features of chondrosarcoma arising from a rib and presenting as a breast mass were reported by Molyneux et al in 1995. However, to the best of our knowledge, the cytology of extraskeletal myxoid chondrosarcoma of the chest wall presenting as a breast mass has not been documented before.

Case: A 30-year-old female presented with left-sided chest pain and a hard lump in the breast of two months' duration. Fine needle aspiration cytology was done, and a possible diagnosis of mucinous carcinoma or mixed tumor of the breast was suggested, with advice to prepare a frozen section before undertaking a radical procedure. On imprint cytology and frozen section a diagnosis of extraskeletal myxoid chondrosarcoma was made and confirmed by histopathology and immunohistochemistry.

Conclusion: It is rare for extraskeletal myxoid chondrosarcoma to occur in the chest wall. This problem is compounded by the fact that cells of extraskeletal myxoid chondrosarcoma which resemble epithelial cells, can very closely mimic some malignant breast tumors.