This is a case of a 48-year old male with left-sided 9.0cm x 8.0cm exophytic, foul-smelling, bleeding breast mass. Core needle biopsy revealed a malignant phylloides tumor. He underwent total mastectomy and final histopathology showed a primary breast leiomyosarcoma staining positive for smooth muscle actin. A review of cases of primary breast leiomyosarcoma was done and to date, there are only 70 documented. The treatment of breast sarcomas still follows those strategies for soft tissue sarcomas in other locations. An important prognosticating factor is complete resection on initial treatment. Lymph node metastasis is rare for sarcomas in general.