A breast biopsy usually refers to a puncture biopsy of a breast mass, often performed under medical imaging guidance to improve puncture accuracy. Most commonly, it is performed under ultrasound guidance. The high resolution of the ultrasound image allows for clear visualization of the position and direction of the biopsy needle, and biopsies performed under ultrasound guidance are highly accurate. When is a biopsy done? 1.A lump is found and its nature is unclear, so it is clear whether it is benign or malignant through biopsy; 2.Before a high suspicion of breast cancer and preparation for neoadjuvant chemotherapy treatment, a biopsy is needed to send pathological examination to confirm that it is breast cancer, and biological indexes of breast cancer, namely estrogen receptor, progesterone receptor, c-erbB-2 oncogene, Ki67, etc., are examined to guide the selection of chemotherapy drugs. Preparation for breast biopsy: Patients need to check bleeding and clotting time, and understand any history of anesthetic allergy, coagulation dysfunction, and other medical history. Biopsy procedure: The lump is centered, disinfected, and toweled. Local anesthesia with lidocaine is usually used, and the patient is awake. The biopsy needle is commonly 14 or 12 gauge. The biopsy needle is inserted through the dermatome and the patient can see the biopsy and feel the physician’s manipulation of the breast area, but without significant pain. Usually 5-8 stitches are needed for puncture and extraction. Compression is applied to stop bleeding when the needle is withdrawn, the puncture site is sterilized again, the needle is withdrawn, gauze is applied and compression is continued for about 20 minutes. Most breast cancers are multiple blood supply lesions, which are prone to bleeding locally and have poor hemostasis when the skin is involved. Malignant tumors are usually hard and brittle, and satisfactory strips of lesion tissue are easily obtained during puncture, while most benign lesions can only be punctured with incomplete strips and dots of tissue that can be easily hemostatic during puncture biopsy. Physicians must communicate more with patients before biopsy to alleviate fears. Most patients are very nervous before biopsy, and with care and encouragement, patients can greatly relieve their nervousness. The punctured tissue is promptly put into tissue preservation solution and sent for pathological examination.