Level 0: Needs to be recalled and re-evaluated in conjunction with other examinations. Indicates that the information obtained from the inspection may not be complete. Grade I: No abnormality is seen (once a year). Grade II: benign changes are considered, and regular follow-up is recommended (6 months to 1 year). Grade III: Benign disease is possible, but a shorter follow-up period is needed (once every 3 to 6 months). The percentage of malignancy at this level is less than 2%. Grade IV: There are abnormalities, and the possibility of malignant lesions cannot be completely excluded, requiring biopsy for clarification (puncture, surgery). Grade IVa: low likelihood of predisposition to malignancy. Grade IVb: moderate likelihood of malignancy. Grade IVc: high probability of malignancy. Grade V: High suspicion of malignant lesion (almost identified as malignant disease), requiring surgical excisional biopsy. Grade VI: Malignant lesion has been confirmed by pathology.