This is the Breast Imaging Reporting Data System (BI-RADS) grading description of breast nodule imaging. There are six grades of breast imaging (ultrasound, mammogram, etc.), which represent the following: grade 1, breast hyperplasia; grade 2, there will be nodules in the breast, but no blood flow is seen, which is definitely benign, and small nodules can be reviewed regularly; grade 3, blood flow is visible in the breast nodules, which is basically The nodules are basically benign, but larger nodules require surgery; grade 4, the nodules are not excluded from malignancy; grade 5, the nodules are most likely malignant; and grade 6, the nodules are confirmed to be breast cancer.
Where grade 4 is further divided into 3 subtypes, 4a, 4b, and 4c. 4a means a malignancy rate of about 20%, 4b means a malignancy rate of about 50%, and 4c means a malignancy rate of about 80%. So when breast imaging reveals breast nodules of type 4a, further examination of mammogram, breast MRI or puncture biopsy or surgical treatment is recommended. If it is clearer that it is a benign tumor, annual review of breast ultrasound or mammogram is sufficient, if it is diagnosed as malignant then further treatment is needed.