Breast adenofibroma, also known as fibroadenoma, is the most common benign breast tumor in young women, with the highest incidence of benign breast tumors. The age of onset is 9-64 years old, with the majority of young people in their 20s. The disease mostly presents as a painless lump in the breast with occasional paroxysmal pain. The tumor grows slowly and most patients discover it unintentionally. It is often solitary, but there are a few cases with multiple occurrences. The lump is roughly round or oval in shape, usually 1 to 3 cm in diameter, with a smooth, nodular, tough, elastic, well-defined border and good activity. Pathologically, there are five types: intraductal adenofibroma, periductal adenofibroma, mixed adenofibroma, cystic hyperplasia adenofibroma, and lobulated adenofibroma. Mammography shows round or oblate high-density shadow with sharp margins and uniform density, which may be accompanied by coarse granular calcification. Ultrasound shows round or oval hypoechoic areas with clear boundaries and uniform internal echogenicity, posterior echogenic enhancement of the tumor, and lateral acoustic shadowing. The diagnosis of this disease is generally not difficult, but a few have difficulties. For those who have difficulties in diagnosis, mammogram palladium film (breast soft film), breast ultrasound and other examinations are feasible. For treatment, surgical excision is effective. Only a very small number of fibroadenomas can become cancerous, and the cancer rate is 0.038% to 0.12%.