RESUMEN
Primary leiomyosarcoma of the nipple-areola complex is extremely rare. Less than ten such cases have been reported in English literature so far. Herein we describe a 52-year-old female presenting with a 1.5 cmx1.1 cmx0.7 cm nodular lesion over her left nipple, and leiomyosarcoma was proved by pathological examination of the excised specimen. Positron emitted tomogram (PET) revealed no abnormal signal other than the primary site. Microscopically, this poorly circumscribed tumor was composed of interlacing bundles of smooth muscle cells with bizarre and pleomorphic nuclei, as well as prominent nucleoli. Its mitotic count was up to 7 mitoses per 10 high power fields (HPF). Immunohistochemical study of tumor cells revealed positive stain for alpha-smooth muscle actin and vimentin; and negative for cytokeratin, CD34 and S-100. Left simple mastectomy was undertaken and no residual mass lesion was noted on the resected specimen. Related literatures about the diagnosis and treatment for breast leiomyosarcoma will be presented here.