Mammary hyperplasia grade 3 is a lump of cystic breast hyperplasia presenting as a grade 3 nodule on imaging, with a high likelihood of being benign and a 0 to 2% risk of malignancy. Breast hyperplasia, also known as cystic hyperplasia of the breast, is a hyperplasia of part of the breast parenchyma due to an imbalance in the ratio of estrogen to progesterone, and is most often manifested by breast swelling and pain and lumps during premenstrual and menstrual periods, and is significantly reduced after menstruation. The BI-RADS (Breast Imaging Reporting and Data System) classification is based on the risk of malignancy of the nodule based on the results of ultrasound, molybdenum imaging, and other breast imaging tests, where a Class 3 nodule is defined as having a high likelihood of being benign, with a <2% likelihood of being malignant. Class 3 breast hyperplasia nodules are generally benign, but sometimes breast hyperplasia lumps are easily confused with breast cancer lumps. Patients are advised to have a follow-up examination within 5 days after the menstrual period is cleared, and biopsy examination should be performed in time if there is any suspected malignant lesion.