In the breast clinic, after knowing the patient’s medical history, the doctor will first perform visual examination, palpation, observation of bilateral breasts, and combined with imaging examinations, including mammography (mammogram) and color ultrasound, which can clearly understand the shape and boundary of breast tissue, the presence or absence of masses, their size, shape and nature, and provide a more reliable basis for differentiation of benign and malignant tumors. Based on the abnormalities found in clinical examination, biopsy, including needle aspiration cytology biopsy and excisional mass biopsy, is the only definite basis for diagnosis of breast cancer.