Breast myoepithelioma. Report of a new case and review of literature

Abstract Breast myoepithelioma is rare. A case is reported of a 71 year old female. The tumor was clinically, radiologically and macroscopically demarcated. Diagnosis was based on histological and immunohistochemical studies. At the time of diagnosis the tumor was composed of myoepithelial cells with few cellular atypias and a low mitotic activity. Tumor cells expressed vimentin, actin, S100 protein and cytokeratin. No local or distant metastases were found. The patient had been treated initially with a large excision of tumor. Local recurrences detected 1 year after initial surgery and showed a similar morphology and immunoreactivity with higher mitotic activity. Mastectomy with axillary dissection was performed. No recurrences and no distant metastases detected 2 years later. Myoepithelial tumors generally considered as benign or low-grade lesion can give rise to a wide range of clinical evolution.