Breast Nodule 3 Classes Irregular morphology with clear margins usually indicates a high likelihood of a benign nodule. Depending on the imaging (ultrasonography, mammography, etc.) presentation of the breast nodule, it can be categorized into 1-6 grades, which is clinically known as the BI-RADS grading system. Grade 1 indicates no abnormal findings on imaging; grade 2 indicates benign; grade 3 indicates a high likelihood of benignity (possibility of malignancy ≤2%); grade 4 is suspicious of malignancy and is categorized as 4A (low suspicion of malignancy), 4B (moderate suspicion of malignancy), and 4C (high suspicion of malignancy); category 5 indicates a high likelihood of malignancy; and category 6 indicates a known malignant pathological biopsy result. Irregular morphology with clear margins is an objective description of nodule morphology and usually represents a nodule pattern that tends to favor the growth pattern of a benign tumor. The results can only be used as a reference for doctors, the specific treatment plan should also be combined with other test results, do not blindly deal with their own, so as not to cause delays in the condition.