Primary rhabdomyosarcoma of the female breast: report of a case and review of the literature.

We report the case of a primary breast rhabdomyosarcoma in a 51-year-old white woman. The tumor occupied the upper outer quadrant of the right breast. There was no association with the underlying pectoral muscle, and the patient was free of any other benign or malignant neoplastic processes outside the breast. Microscopically, the breast tumor was composed of primitive myoblasts and numerous rhabdomyoblasts at various stages of development, many of which exhibited cytoplasmic cross striations on routine hematoxylin-eosin staining.