Xanthogranulomatous mastitis in 41-year old female 34 weeks pregnant with pain in upper inner quadrant of left breast.Hypoechoic well-circumscribed lesion was seen in 2:00 position of left breast with surrounding and internal increased vascularity. This was thought to be likely related to lactational changes. However, due to presence of increased vascularity, this lesion was biopsied and histology revealed xanthogranulomatous mastitis.