Intraductal papilloma occurs in women of any age after puberty, but is more common in menstruating women, especially in the age of 40-50. This disease has a malignant rate of 5-10% and is called a precancerous lesion. Clinical attention should be paid to this disease and the masses should be examined by needle aspiration cytology or biopsy if necessary. It is generally believed that this disease is related to estrogen overstimulation. Intraductal papillomas are benign papillomas that occur in the ductal epithelium of the breast. According to the number of lesions and their location, they can be divided into two types: solitary – large intraductal papillomas; and multiple (papillomatosis) – medium and small intraductal papillomas. The former originates in the abdomen of the milk ducts and is mostly solitary, located in the subareolar area, and malignant changes are rare; the latter originates in the terminal ducts of the breast and is often multiple, located in the peripheral area of the breast, and is more prone to malignant changes. In the case of solitary large intraductal papilloma, a 1 cm long corpuscular mass can be found in the subareolar or marginal area of the areola, or a nodule the size of a date nucleus can be found, and due to the accumulation of blood and fluid in the duct where the tumor is located, blood, milk or coffee-like discharge can be released from the nipple when the mass is pressed, but the discharge port is fixed. This disease is often intermittent spontaneous overflow, or overflow after squeezing or bumping. Most patients are found to leave a brownish-yellow stain on their underwear found at the clinic. The overflow is discharged, the tumor becomes smaller, the pain is not obvious, occasionally there is pressure pain, hidden pain, and malignant transformation of this evidence is rare.