We report a case of non-palpating breast cancer with huge lymph node metastasis. The patient was a 58-year-old woman who had a huge tumor at her right armpit. The tumor was 4 cm in diameter. Aspiration biopsy cytology for the tumor was performed. The diagnosis is Class V. Mammography showed an ill-defined mass at her right breast. Ultrasonography revealed a low echoic mass at the C area of her right breast. A core needle biopsy for the breast tumor led to a diagnosis of an invasive ductal carcinoma positive for estrogen receptor and progesterone receptor, and negative for HER2/neu protein expression. She received 4 cycles of CEF (E: 60 mg/tri-weekly) plus 12 cycles of paclitaxe (l80 mg/weekly). After chemotherapy, she received muscle preserving mastectomy plus axillary lymph nodes dissection. In histopathology, there were no carcinoma cells in resected breast tissue and resected lymph nodes. Therefore, the effect of chemotherapy was diagnosed as a pathological complete response. After operation, she was administered aromatase inhibitor. The patient has been well and remained disease-free during a follow-up period of 6 years.