The clinical application of breast duct endoscopy has solved three major problems: 1. It has solved the problem that the lesions in the breast ducts can only be diagnosed indirectly but cannot be visualized, and opened up a new diagnostic pathway for the characterization of the lesions in the breast ducts. 2.It solves the problem of localization of lesions in the milk ducts, and reduces the scope of surgery for most of the patients who need surgery. 3. Modified some surgical indications for breast diseases, so that some patients can avoid unnecessary surgery. Patients with inflammation and breast hyperplasia in the milk ducts can be exempted from surgery, patients with benign lesions in the milk ducts can have the scope of surgery narrowed down, and patients with early malignant tumors can be detected and treated in time, and radical mastectomy can be chosen to preserve the breast. This relieves patients from unnecessary pain and does not affect the aesthetics of the breast. In the past, segmental resection was often chosen, which was relatively blind, especially when the lesion was small, it was often missed, and in some cases, even if the lesion was resected, it might be missed when selecting the material for the pathological section, which brought a lot of troubles to the clinic; now, the localization needle is placed under the mastopexy through the milk hole, which can cut the milk ducts along the guidewire, and if the guidewire is not easy to be touched by the thin and soft guidewire, it can be used to assist in the dissection of the milk ducts by using the outer coat tube along the guidewire, and the immovability of the hooked needle It can enable the operator to accurately find the site of the lesion under breast ductoscopy for excision and sending pathology, reduce the leakage of diagnosis, narrow down the scope of the operation, and reduce the trauma to the breast. The main use of microfiber breast duct endoscope 1, confirm the site, scope and nature of lesions in the lumen of breast duct. 2.Diagnose benign tumors, malignant tumors and precancerous lesions in the breast duct. 3.Papillary tumor, papillary carcinoma, breast cancer, atypical hyperplasia of the epithelium in the milk ducts (precancerous lesions), etc. 4.Qualitative and localization diagnosis of nipple discharge. 5.Monitoring endocrine, immune and pathological indicators of breast cancer patients. Treatment of benign nipple discharge and breast cyst. 7, Treatment of breast pain. 8.Treatment of occlusive milk duct inflammation, mastitis, subareolar abscess. Clinical use description In clinical practice, because of breast pain, lumps and the consultation of the patient is quite common, most of the patients do not have nipple overflow (or milk-like overflow), ultrasound examination almost all diagnosed as breast hyperplasia, milk duct expansion, many patients take a variety of drugs for a long time, the effect is very little or ineffective. The endoscopy can be used for the diagnosis and treatment of various breast diseases, and is not limited to the diagnosis of patients with simple nipple overflow. Mammography can make clearer diagnosis of breast duct dilatation, papilloma, papillomatosis and breast duct cancer, especially for the diagnosis of breast duct cancer, which really realizes the early detection of breast cancer caused by breast duct diseases. The clinical application of lactoductoscopy can greatly improve the accuracy of the diagnosis of the etiology of nipple discharge patients. Mammography can clarify the size and number of lesions as well as their distribution and localization, thus guiding the scope of surgical excision. For multiple breast cysts with no malignant manifestations on cytological examination of the puncture fluid or the flushing fluid, intramammary duct therapy is also an effective means and can minimize the scope of surgical excision. Patients with breast pain and breast lumps without nipple discharge can be correctly diagnosed and reasonably treated by lactoductoscopy combined with ultrasound and cytology. Mammography can be used as a routine examination for married women. For benign diseases without nipple discharge, interventional therapy, even if the obstructed milk ducts are unblocked, can significantly improve the symptoms and delay or block the adverse stimulation of the mammary glands caused by the ductal factors.