RESUMEN
A twenty-nine-year-old Bahraini female presented with painless right breast lump of thirteen years duration. The lump was 7.5 cm, well-defined, mobile and located in the lower inner quadrant of the right breast with no palpable axillary lymph nodes. Breast ultrasound findings revealed right breast hypoechoic mass slightly irregular and lobulated with minimal cystic changes, vascularity and faint focal calcification. Fineneedle aspiration cytology was C2 [benign]. The lump was surgically removed. The lump measured 55x55x32 mm, lobulated, firm and tan colored tissue. Histopathology revealed benign tumor formed of mixed epithelial and stromal components. Immunohistochemically, the stromal spindle cells were strongly positive for smooth muscle myosin. Microscopic and immunohistochemical findings proved that the abundant stromal elements were smooth muscle cells