A breast ultrasound suggesting a BI-RADS classification of category 4a means that the nature of the breast nodule is to be determined, with a low suspicion of malignancy (malignancy rate of 2-10%), and that crude needle aspiration or lumpectomy needs to be considered on a case-by-case basis. The BI-RADS classification of the breast is now a universally recognized standard for grading breast disease with more accurate results. It is categorized into grades 0 to 6 based on the likelihood of malignancy. Grade 0 evaluation is not completed, need to be combined with other imaging; Grade 1 is normal presentation; Grade 2 (benign lesions) such as simple breast cysts, lipomas, etc.; Grade 3 (high probability of benign, malignant rate <2%), it is recommended to follow up for 3-6 months, and regular re-examination; Grade 4 is classified into 4a, 4b, 4c, the rate of malignancy may be sequentially higher; Grade 5 is highly suspected of malignant (>95%); Grade 6 is confirmed to be malignant by histology. . If the diagnosis of breast ultrasound BI-RADS classification is 4a, we should consult a doctor in time, and choose the best surgical method under the guidance of a physician to perform coarse needle aspiration or lumpectomy to clarify the nature of the disease for follow-up treatment.