The basic diagnosis of ductal carcinoma of the breast is sometimes made by physical examination, and sometimes after some auxiliary examinations, including color ultrasound, molybdenum target, magnetic resonance imaging or catheteroscopy. All these examinations are only a kind of imaging or physical examination, and they are only a kind of clinical inference for the diagnosis of the disease. The real diagnosis can only be confirmed through pathological examination, including hollow needle puncture, coarse needle puncture and surgical excision of tissues for biopsy, and pathological diagnosis is the only verification standard for breast cancer diagnosis.