A 61-year-old woman was visited our hospital for a left breast tumor. Ultrasonography (US) demonstrated two tumors comprising a tumor 3.3 cm in diameter in the A area and another one 0.9 cm in diameter in the C area of the left breast, and US-guided core needle biopsy (CNB) was performed. The histological findings showed invasive ductal carcinoma, ER (+)/PR (-)/HER2 (+) in the A lesion and ER (+)/PR (+)/HER2 (-) in the C lesion. At this point in time, US demonstrated a new tumor 1.9 cm in diameter in the outside C area of the left breast, and CNB was performed. The histological findings showed invasive ductal carcinoma, ER (+)/PR (+)/HER2 (-) in the outside C lesion. Chemotherapy was estimated as PD, and an operation was performed (Bt + Ax). Histopathological examination showed pCR in the A lesion, invasive lobular carcinoma in the C lesion and solid-tubular carcinoma in the outside C new lesion. Depend on each subtype, HER2/new targeting trastuzumab therapy, radiation therapy and ER/PR targeting hormone therapy were tried as a post operative treatment.