Breast BI-RADS classification is the standard of breast imaging for the degree of benign and malignant breast tumors. BI-RADS4a means the category of suspicious malignancy, the chance of malignancy is relatively low, around 4%-10%. The diagnosis of BI-RADS4a suggests the need for biopsy. The examination method can be chosen from coarse needle aspiration biopsy, surgical excision and sent to pathology or minimally invasive rotary mastectomy for further treatment according to the results of the pathology examination, if the pathology result is benign and reliable, continue to follow up and observe. If the test result is malignant, further surgery is needed. When the mammogram suggests BI-RADS4a, you need to pay attention to timely examination in regular hospitals to achieve early detection and early treatment.