Small breast cancers (also known as non-palpable Ca foci) are generally very small lesions with a diameter of 3mm-10mm. The incidence of breast cancer has increased in recent years and there are various screening methods, but the rate of small breast Ca diagnosis is still low. If cancer foci <11mm in diameter are not palpable during physical examination, ultrasound is an extremely valuable addition to the physical examination of the breast and the radiographs of the mammogram. Advances in high-resolution ultrasound and transducer technology allow ultrasound to distinguish breast cancer foci as small as 3mm in diameter. Therefore, it is very important to screen for breast diseases, especially small breast cancers, and it is of great clinical significance to improve the detection rate of benign and malignant nodules. What are the characteristics of ultrasound sonogram of small breast cancer? How to make a good identification in ultrasound examination? (1) Pathological features: (1) Small size, soft and movable; (2) Hidden in the surrounding solid glandular tissue; (3) Commonly, small infiltrating Ca, in situ Ca (CIS, including intraductal Ca, pink Ca, lobular in situ Ca), colloid Ca (mucus Ca), medullary Ca. (2) Sonographic features: (1) Hypoechoic, microcalcified foci; (2) Burr-like margins, distant with acoustic shadow, anterior-posterior diameter ≥(3) If the 4mm-6mm border is smooth and the acoustic shadow is not obvious (4) Internal blood flow signal Although small breast Ca has its own sonographic features, it lacks specificity and is similar to larger breast Ca in terms of features, thus causing more problems in practice. So how exactly can we make a good differentiation during the examination? At present, ultrasound-guided fine-needle aspiration cytology or focal center biopsy, or ultrasound-guided localized open biopsy are used, why must ultrasound guidance be used to complete this examination? Because the volume of small breast Ca is quite small, the texture is soft, and the activity is large, it is difficult to find the lesion during surgical excision, and the normal tissue of the gland is often removed, which will not only get no therapeutic effect but also lead to the spread of malignant tumor cells or implantation. Since the healing of breast Ca patients is directly related to the size of Ca foci, it is especially important to avoid this undesirable consequence, and to implant specific filaments in the center of breast cancer foci under ultrasound guidance, and then remove the "cancerous" foci centered on the filaments. This approach is now popular and successful, allowing most patients with small breast Ca to be diagnosed and treated sooner. The early diagnosis of small breast Ca is very important, because at present there is a fluke mentality and inertia in people's understanding, which often makes small breast Ca not diagnosed early and delayed timely treatment, and finally it is difficult to preserve the breast to cause lifelong regret, so I think: breast examination must go to a regular professional hospital or general hospital to do ultrasound examination, or even combined with mammograms, laboratory tests and other comprehensive analysis, to avoid As an ultrasonographer, you must be able to examine your breast in a comprehensive and systematic manner without leaving any dead ends, fully utilizing the weapons in your hands from 2D to CDFI and then to PW, thinking backwards from the boundary, morphology and blood flow, and ruling out one by one from the history, symptoms and signs, only then can we correctly diagnose and find small breast Ca, and early surgery predicts that you will have a 100% breast with a higher rate of malignant removal, as well as a much higher quality of survival. For women, breast health is so important, it is like their own life, the loss of breast will bring them great pain, I hope we take up this mission together and make further efforts for women's health!