LEIOMYOSARCOMA OF THE FEMALE BREAST - REPORT OF 2 NEW CASES AND A REVIEW OF THE LITERATURE

We present the clinical, light microscopic, and immunohistochemical fe atures of two new cases of leiomyosarcoma of the female breast. Both t he patients were old (83 and 86 years) and were referred with a histor y of a long-standing breast lump. The results of the physical examinat ion and the preoperative radiologic investigations suggested a phyllod es tumor. The patients were treated with mastectomy. The tumors measur ed 6 and 6.5 cm in the largest dimension, respectively, and were compo sed of fascicles of atypical, actively proliferating spindle cells, of ten intersecting at right angles. The axillary lymph nodes were free o f tumor. Immunohistochemically, the tumor cells were positive for desm in, muscle-specific actin, and vimentin and negative for other markers , including keratins and hormone receptors. Focal rhabdomyoblastic dif ferentiation was noted in one case. Fellow up at 1 year is negative fo r metastases or local recurrences. Our study confirms that leiomyosarc oma of the breast is a locally invasive neoplasm and that it could rep resent a peculiar anatomic entity among mesenchymal tumors of the brea st.