BI-RADS Category 4A means that the breast nodule is Category 4A, the nodule is of low malignant potential, and the probability of malignancy is 2 to 10%. BI-RADS (Breast Imaging Reporting and Data System) is an assessment of the risk of malignancy of a breast nodule based on the results of breast ultrasound, mammogram and other imaging tests. Category 4A refers to breast nodules that are of low malignant potential, with a malignant probability of 2-10%, i.e., there exists a 2-10% chance that a category 4A nodule is malignant, such as breast cancer, and in most cases, it is a benign nodule due to breast hyperplasia, fibroids, and so on. In general, it is recommended that patients with category 4A nodules undergo puncture biopsy and choose treatment according to the benign or malignant nature of the pathologic results. Patients are advised to consult a specialist for further examination and treatment as prescribed by the doctor.