Core needle biopsy Core needle biopsy (CNB) is a method to remove a sufficient amount of tissue from a breast lump for a more accurate qualitative diagnosis without surgery by using a biopsy needle, i.e., aspirating the pathological tissue and other components of the lesion through a hollow needle to make a section for pathological histological examination, and its greatest advantage is to obtain a histological diagnosis. The birth of hollow core needle has changed the previous surgical biopsy as the only method to obtain histological pathological diagnosis, and is also an early expansion of minimally invasive technology in breast tumor diagnosis. It includes conventional CNB biopsy, US-CNB (ultrasound-guided CNB) or SCNB (X-ray stereotactic CNB). The most commonly used one is US-CNB. (I) Evaluation of advantages and disadvantages 1. a. Compensate for the limitations of FNA diagnosis: Since FNA obtains cytological diagnosis, it cannot distinguish between carcinoma in situ and invasive carcinoma; CNB obtains histological diagnosis and can do pathological section examination for pathological typing, estrogen and progesterone receptor status analysis as well as immunohistochemistry and genotyping, which can not only make more definite histological diagnosis but also distinguish between primary carcinoma and invasive carcinoma. It can not only make more definite histological diagnosis, but also distinguish in situ cancer from invasive cancer, provide diagnostic basis for neoadjuvant chemotherapy, biopsy of anterior lymph nodes and patients with metastatic recurrence, and detect prognostic indicators for comprehensive evaluation and formulation of individualized treatment plan. b.Significantly reduce the number of surgical biopsies and decrease the cost of diagnosis. c. Fast, accurate, minimally invasive, small or even no significant changes to the breast structure, etc. 2. Disadvantages Needles need to be repeatedly inserted and exited several times (generally 3-5 satisfactory tissue strips need to be obtained), which increases the pain of patients. (B) Indications: 1. palpable breast masses and imaging suggests intra-mammary occupying lesions in the corresponding area, requiring minimally invasive biopsy or minimally invasive excision for definitive diagnosis. 2. Those who do not have a palpable lump and have an ultrasound finding of an unpalpable suspicious occupying breast lesion with a Breast Imaging Reporting and Data Analysis System (BI-RADS) rating of four or higher, or three, if requested by the patient or other clinical considerations. Biopsy may also be considered. 3. Those who do not have a palpable mass, and mammography reveals suspicious microcalcified lesions, BI-RADS grade IV or higher, and the breast does not have a palpable mass, and mammography reveals other types of lesions with BI-RADS grade IV or higher (such as masses, structural distortion, etc.) and cannot be accurately localized under ultrasound; some BI-RADS grade III lesions, if requested by the patient or other clinical considerations. Biopsy may also be considered. (C) Contraindications Patients with severe systemic diseases and serious bleeding disorders and patients with proposed local infection by puncture should not undergo this examination.