Nipple discharge as the first symptom accounts for 3% to 14% of breast diseases and is second only to breast lumps and breast pain in terms of incidence. Nipple discharge mostly occurs in breast hyperplasia, intraductal papilloma, breast inflammation, ductal dilatation or breast cancer, while bloody nipple discharge is commonly seen in intraductal papilloma or breast cancer. Ductoscopy, also known as electronic breast fiber endoscopy, has replaced mammography as the preferred means of diagnosing the cause of nipple discharge. It is easy to operate, less invasive and intuitive, and effectively improves the diagnosis of augmentation lesions in the ducts. It can also be used for the treatment of benign ductal lesions, such as minimally invasive excision of diseased ducts, treatment of plasmacytoid mastitis, and localization of tumor guidewires in the ducts. The structure of the ductoscope includes the image transmission and light guide part, the camera and light source part, the image display part, and the image management and output part. Ductoscopy procedure Ductal endoscopy is performed by inserting a 0.75mm (0.6mm or 0.95mm) diameter endoscope through the opening of the breast duct and probing into the end of the breast duct through a medical monitor while observing the situation inside the breast duct, as far as the fourth or fifth branch of the breast duct. The entire procedure takes about 10 to 15 minutes without the need for local anesthesia and without any pain or discomfort to the patient. Ultrafine endoscopy is composed of ultrafine optical fiber transmission beam, light guide beam, tiny self-focusing mirror and lens. Through endoscopic examination of breast ducts, the condition of breast duct wall and ductal secretion can be clearly observed, and its color, size, shape and smoothness can be described if there is an occupying lesion. Breast ductal carcinoma, intraductal papilloma, and ductal inflammation each have their own characteristic endoscopic manifestations of the breast ducts, and thus can be diagnosed accordingly. The other functions of endoscopy are biopsy of the lesion under endoscopic guidance for pathological confirmation, marking of the lesion on the skin of the body or positioning a guide wire under the ductoscope for accurate positioning for surgery, and treatment of benign diseases in the duct through the ductoscope. Who needs lactoscopy and treatment? In patients with nipple discharge of all colors, especially bloody discharge, the incidence of intraductal neoplasia is more than 90%, and in patients with colorless and yellow discharge, more than half of them have intraductal neoplasia. All tumors in the milk ducts require surgery. The significance of lactoscopy is 1) to clarify the cause of nipple discharge; 2) to refine the indications for surgery and reduce unnecessary surgery; 3) to narrow the scope of surgery and accurately remove lesions; 4) to perform exploratory treatment for some special types of diseases; 5) to perform some minimally invasive treatment and minimally invasive surgery with the help of lactoscopy. What kind of treatment can be done by lactoscopy? 1.Lacteal duct lavage, cytological examination, clear diagnosis, and can achieve certain therapeutic effects; 2.Plasmacytoid mastitis and other diseases, lesioned milk duct flushing, and injection of antibiotics and other drugs; 3.The use of lactoscopic mesh basket to remove large pieces of flocculent or unclogging the milk duct; 4.Lactoscopic crochet to locate neoplastic lesions, accurate removal of lesions; 5.Lactoscopy-assisted minimally invasive excision of diseased milk ducts.