The author recently encountered a case over 40 years of age with a previous history of breast adenoma. A year ago, there was intermittent hematochezia in the right nipple with blood visible on the underwear. ultrasound revealed adenoma nodules in the medial quadrant of the right breast. The patient was admitted to the hospital for fear of bloody overflow. The medial adenoma nodule of the breast was removed on the operating table. Simultaneous mammography revealed blue-stained dilated ducts with no masses. On exploration of the nipple root, a tough nodule the size of a green bean was found, which was pathologically confirmed as an adenoma of the nipple. Papillary duct adenoma, also known as papillary adenoma, celiac adenomatosis, papilloma, and subareolar duct papilloma, is a benign tumor that occurs from the ductal epithelium of the nipple. It is rare and its incidence accounts for about 1% of benign tumors of the breast. There are reports of malignant transformation. Ou Jianghua, Department of Breast Surgery, Xinjiang Cancer Hospital Patients are usually middle-aged women, mostly aged 40 to 50. The course of the disease is long. The nipples may be enlarged or change in orientation, and a few may have nipple erosion, crusting and nipple discharge. Hard nodules can be found at the nipple. In some patients, there are no obvious changes in the nipple surface. It is often misdiagnosed as papillary Paget’s disease. The disease is a benign tumor of the nipple and can be cured by surgical removal of part of the nipple tissue including the tumor. It must be differentiated from Paget’s disease and should be diagnosed pathologically before performing the appropriate surgery. Benign tumors originating from the ducts of the nipples or the infundibular sinuses are seen at any age after puberty, with a peak in the premenopausal period (40-50 years of age), most of the patients are women, occasionally men (< 5%), the lesions are usually unilateral, and bilateral ones are extremely rare; the tumors rarely exceed 1-115 cm, with a medium texture and unclear borders; the common feature is the long duration of the disease, most of them reaching more than 1 year, and the clinical manifestations are The clinical manifestations include nipple discharge (may be bloody), erosion, rupture, and small nodules palpable in the nipple. This tumor is difficult to diagnose preoperatively and is easily confused with eczema-like carcinoma and intraductal papilloma, while pathologically it needs to be differentiated from nipple sweat-like adenoma and breast cancer. 2. The papillae are swollen, thickened, eroded, hardened, or even ulcerated, and a type of small round nodule or thickened area, well-defined or indistinct, without envelope, with a diameter of 0.5 to 2.5 mm, can be seen under the nipple or nipple skin. The diameter is 0.5 to 2.5 mm. The area is firm, grayish white or grayish yellow in texture; occasionally there are small sacs or dilated ducts. 3. Microscopically, the tumor is mainly composed of tightly arranged, disorganized hyperplastic ducts surrounded by a variable amount of fibrous mesenchyme. The ducts are lined with both glandular and myoepithelial epithelial cells. The glandular epithelium is mostly rectangular or columnar in shape, and the epithelial cells are proliferated to varying degrees in the form of papillae or solid nests, which grow and compress or obstruct the collecting ducts, causing them to dilate and form a hard nodule. Based on the structure of the lesion, Rosene classifies papillary adenomas into three types: adenopathy, sclerosing papillomatosis, and papillomatosis. 4 ． Differential diagnosis ( 1 ) Papillary duct adenoma with papillary erosion, crusting or ulcer formation is clinically similar to papillary P a g e t disease, but the former does not have P a g e t cells in the papillary epidermis, nor does it have ductal carcinoma in the deep mammary gland. Although clear cells are similar to P a g e t cells, their immunohistochemical staining C K 7 , C K 8 , C K 1 8 is overexpressed, while H e r - 2 , C E A is negative. ( 2 ) The tumor should be differentiated from invasive carcinoma when it shows sclerosis and pseudo-infiltration. The former occurs in the nipple and areola, and although the cells are abundant, they are complex in composition and the residual duct wall is still visible. 5. The common symptoms are bloody or plasma nipple discharge, nipple erosion, crusting, thickening and hardening, or the presence of subpapillary nodules. This tumor is benign, but recurrence may occur if excision is incomplete. This tumor is closely related to breast cancer, and the literature reports that nipple adenoma combined with breast cancer accounts for 16.5% to 19% of cases. This is probably because male breast cancer is more commonly found in the areola area. Therefore, breast surgeons should have an observant eye and a logical thinking mind, and ask more questions when the clinical symptoms of a patient do not match the clinical examination. Repeated communication with the ultrasound surgeon and personal inspection of the ultrasound is the key to solving the problem. For patients with bloody nipple overflow, ultrasound examination of the nipple itself should not be missed.