There are three types of preoperative puncture for breast masses, each with its own advantages and disadvantages, and their techniques, which are analyzed as follows: 1.Fine Needle Aspiration Biopsy (FNAB), fine needle aspiration biopsy Advantages: the chance of needle recurrence is 0.005 %, no statistical basis; Disadvantages: insufficient amount of tissue, unable to perform immunohistochemical examination 2.Core Needle Biopsy (CNB) empty needle aspiration biopsy Advantages: sufficient amount of tissue for immunohistochemical examination; ER and PR match rate is greater than 90% Disadvantages: 22% needle tract implantation, however, CNB does not affect local recurrence after breast conservation + radiotherapy after aspiration; false negative is 3-4% Tips: ( (1) needle tract as vertical as possible; (2) tissue taken 4-6; 4 tissues, 14 Gauge (1.6284mm), 95% confirmed, 2-3% do not penetrate positive cells (3) check the specimen penetrated: sinker is glandular, floating is fat (4) if the puncture is calcified foci, must be photographed, and mark the original site of the lesion, determined follow-up, to avoid causing histological underestimation (puncture results for DCIS) (5) The puncture should not be done to the posterior space, otherwise it will easily produce hematoma. (3) Mamotone has advantages: the possibility of tumor epithelial implantation is small because the needle is not repeatedly inserted and removed; its negative pressure can suck the mass closer and avoid air entering the residual cavity resulting in unclear view of the puncture; disadvantages: the needle is thick and cutting a large amount will lead to an increased chance of contact between tumor cells and blood. In summary, there are advantages and disadvantages of various punctures, and CNB can be given priority in terms of selection.