Nipple discharge is a common complaint of patients attending the breast clinic. It may seem minor and harmless, but it can cause discomfort and inconvenience to women, and worse, there is a possibility of tumors, including malignant tumors, behind it. Previously used smear positivity of the overflow was not high, and ductal mammography, even if successful, had only indirect evidence. Therefore, the choice of treatment was based on clinical experience, which inevitably led to delayed treatment or loose surgical indications. Since the introduction of fiberoptic ductoscopy into the clinic, a breakthrough has occurred in the diagnosis and treatment of nipple overflow. Definition: Lactoscope, also known as microfiber endoscopy or fiberoptic lactoscope, is a tiny endoscopic device that observes the lumen and wall of the breast ducts by means of ultrafine fiber-optic fibers. Structure: The structure of lactoscope: it is composed of cold light source, image monitor, image recorder and optical fiber, etc. It is also equipped with various types of breast tube dilators and special positioning needles. Examination method: 1. Body position: lying position or sitting position. 2. 2.Routine sterilization, laying cavity towel. 3.Find the opening of diseased milk duct, under local anesthesia, gradually dilate the overflowed milk duct from fine to coarse with No.6~12 ophthalmic lacrimal probe, insert the endoscopic coated tube, and flush the milk duct with physiological saline to dilate the opening part of the milk duct to 0.45~0.55mm. No local anesthesia is needed, only some discomfort when entering the nipple part. 4.Observation of lesions in the milk ducts: observe the wall and lumen of the ducts. After abnormal hyperplastic lesions are found, observe the trait, size, shape, color, quantity, and the proportion of the mass in the whole lumen of the duct. Meanwhile, the distance between the lesion and the opening part of the milk duct and the projection of the body surface are confirmed. 5.Treatment under lactoscopy: if the lesion is inflammation in the duct, gentamicin 80,000u can be used to add into the flushing solution to flush repeatedly, and leave a little in the catheter. If the lesion is a small papilloma with tip, it can be eradicated by lactoscopy or sucked out by negative pressure with a biopsy needle against the lesion. Fourth, the examination results: various types of breast ducts under the microscope performance: 1, “normal” milk ducts performance: lactoductoscopy can observe the range of milk ducts from the opening part of the milk ducts to 5 ~ 6cm. most of the milk ducts for the two branches, there are also a number of branches of the fork, and its direction is very complex and it is difficult to see the regularity. The wall of the ducts is smooth, the surface is bright, and may be slightly pinkish, the capillaries are clearly visible, and the lumen is smooth and basically free of flocculent secretion. Ductal constrictions are present in the nipple, and it is usually possible to see what appears to be a straight pleat in the internal nipple and what appears to be a whorled pleat in the main ductal portion of the nipple. This group of information can be as deep as 6 grade branches. 2. Dilatation of the ducts: Dilatation of the ducts, lumen is clear, wall is smooth. There is localized narrowing of the nipple ducts and a little white flocculent material in the lumen. 3.Ductal inflammation performance: local or extensive congestion, the lumen may have more exudate, yellow, red, red and white. The wall of the duct is not smooth, and in some serious cases, the normal structure is lost to be black and gray flocculent, and the lumen of the duct may be narrowed or occluded locally. 4.The performance of papilloma and neoplasia in the breast tube: papilloma is generally yellowish, can be mixed with red or purple, the surface is still smooth can be accompanied by congestion, hemorrhage. It is hemispherical, and also has the shape of round, cauliflower pattern and so on. Larger ones can occlude the lumen, but there is a very small gap between the wall of the milk duct and the tumor. Tumors are most often found in grade 1 to 2 ducts. The location of intraductal papillomatosis is deep, the number is more than 2, the shape is similar to that of papilloma, and the lumen wall around the tumor is still smooth. 5, Manifestation of intraductal carcinoma: The lesion extends longitudinally along the inner wall of the duct lumen into grayish-white irregular protrusion, forming a bridge-like structure. There are erosion and punctate hemorrhage on the surface. The role and advantages of lactoductoscopy: 1. The observation scope is from the opening of the nipple duct to the distal 5-6 cm, and the maximum depth of insertion is 4.5±1 cm on average, which can basically meet the clinical needs. 2. 2.Observe the inner wall and view lumen of all levels of breast ducts under direct vision. 3.Combined with cytological examination of ductal fluid flushing, biopsy of suspicious lesions, to provide basis for preoperative clarification of the nature, number and location of lesions. 4, Fiberoptic endoscopy can observe the lumen and wall of breast ducts through ultrafine optical fiber, which improves the accuracy of diagnosis of the cause of nipple overflow patients. 5, fiberoptic endoscopy as a kind of micro endoscopy, with easy operation, small trauma, can find small lesions in the breast tube, may become a new method to diagnose nipple overflow instead of X-ray mammography. 6.Fiberoptic lactoscopy is better than cytology and ultrasonography for the diagnosis and differential diagnosis of nipple overflow, and it is an effective and safe examination method for patients with nipple overflow.