(A) Ductoscopy, also known as electronic breast fiber endoscopy, has now replaced ductography as the preferred means of diagnosing the etiology of nipple discharge. Breast duct entry is easy to operate, less invasive, intuitive and effective in improving the diagnosis of augmented lesions in the milk ducts, and can also be used for the treatment of benign breast duct lesions. (b) The object of breast ductoscopy, with nipple overflow as the primary symptom of consultation accounts for 3%-14% of the main line of disease, the incidence of which is second only to breast lumps and breast pain. Nipple discharge occurs most often in mastocytosis, intraductal papilloma, breast inflammation, ductal dilatation, or breast cancer. (3) The significance of mammography (1) Various kinds of nipple overflow, especially bloody nipple overflow, yellowish overflow, the incidence of neoplastic lesions in the milk ducts is 1/3-1/2. In addition, many patients with white overflow have lesions caused by masses in the milk ducts, all of which require surgical treatment after mammography. (2) Most of the masses in the areola area with nipple discharge are intraductal tumors or fibroadenomas, which are closely related to the milk ducts. Lactoscopy can clarify the diseased milk ducts, thus guiding the surgery and accurately removing the mass and diseased milk ducts. Reduce the chance of local recurrence after surgery. (3) In patients with periareolar plasma cell mastitis, plasma cell mastitis is caused by blockage of the proximal end of the milk ducts and accumulation of secretions and inflammatory cells in the milk ducts, which results in acute and chronic inflammation of the breast. The lactoscope can lavage and collect the exfoliated cells in the milk ducts for cytological examination to clarify the diagnosis, and can also flush and unblock the diseased milk ducts to achieve drainage. At the same time, antibiotics and other drugs can be injected to reduce inflammation. In addition, if the inflammation is limited, the diseased ducts can be clearly identified under lactoscopy and surgically excised to remove the diseased ducts and local scar tissue. (4) Canker sores are a type of breast enlargement, partly due to blockage of the proximal milk ducts and poor drainage of the distal milk ducts. Lactoscopic lavage of the milk ducts can help to clarify the diagnosis. It can also achieve some therapeutic effect. (5) For patients with cumulative breast cysts, unblocking the milk ducts can improve the symptoms. (4) We introduced lactoscopy from abroad in 1997 to carry out the diagnosis and treatment of nipple overflow. We have performed nearly 10,000 cases of intraductal tumor surgery. At the same time, numerous patients with dilated breast ducts with chronic inflammation were treated with irrigation and anti-inflammatory treatment, eliminating the need for painful surgery. The authors would like to emphasize that patients with nipple overflow must pay attention to it, especially middle-aged and elderly women, and must visit a specialist hospital for an early lactoscopy. (The cost of lactoscopy is just over $100, covered by medical insurance, and the examination takes about 15 minutes.)