A 62-year-old woman presented to our clinic with a palpable left breast mass and mild skin erythema which she had noticed 5 days earlier and which had been growing since then. She denied any recent trauma. Diagnostic mammography showed an obscured mass (Figure 1), and ultrasound demonstrated a 3.5 cm hyperechoic mass with indistinct margins and increased vascularity (Figure 2). Ultrasound-guided core needle biopsy was performed. Histological examination revealed large, plump polygonal cells with prominent nucleoli and background myofibroblasts infiltrating fibroadipose tissue (Figure 3A-F). The cells were positive for vimentin and negative for keratin AE1/AE3, keratin 5/6, CAM5.2, p63, S100,