Chondrolipomatous tumor of the breast with myoid differentiation

Benign human breast lesions containing chondroid tissue are uncommon. Their classification and nomenclature are confusing. We report a case of a voluminous, well circumscribed painless breast mass in a 47-year-old woman. The mass had been present for nine years and measured 17 x 8 x 6 cm. Histologically it was composed of breast parenchymal elements, fat mature cartilage and fibrous tissue with small fascicles of eosinophilic spindle-shaped cells intensely stained with actin and desmin antibodies. A careful review of the literature showed only one similar case reported by Metcalf and Ellis in 1985 and called "choristoma". We discuss this terminology and the other breast lesions containing cartilage.