Plasmacytoid mastitis is not a bacterial infection, but a non-bacterial inflammation of the breast, a special type of mastitis, named for the large number of plasma cells infiltrating the tissue surrounding the inflammation. It is mainly characterized by nipple discharge, subareolar masses, parareolar abscesses and fistulae. Etiology The etiology and pathogenesis of plasmacytic mastitis are not fully understood. One theory is illustrated below. Clinical manifestations The lumps often form with uneven margins and an unsmooth surface, mostly near the areola. The affected ducts are dilated and may cause nipple discharge, which is mostly plasma, brownish-yellow or bloody. A large number of plasma cells are seen on cytologic smear. In some cases, the mass gradually disappears after a few months, and some may recur. In late stages, the masses soften and form abscesses. The abscess breaks down and flows mixed with powder-like pus and causes fistulas in the areola, and the lesions can also occur in multiple places, forming multiple fistulas and even interconnecting with each other, leaving the breast full of holes. The clinical features 1, mostly in non-lactating women, can be seen in unmarried non-lactating women, but also in men. Most patients have a deformity of the nipple or dilated milk ducts. 3. Recurrent fistulas or masses next to the areola that do not heal for a long time. 4. Severe damage to the appearance of the breast – multiple incisions and ruptures, multiple scarring, distorted nipples, and breast deformity. Breast disfigurement is even more serious if lesions are multiple and repeated incomplete surgeries are performed. Definitive diagnosis Plasmacytoid mastitis can be diagnosed by mammography, ultrasound, CT, fiberoptic ductoscopy and other ancillary tests, but pathology is currently the standard. Early pathology shows varying degrees of dilation of the breast ducts, with lipid-laden secretions collecting in the lumen with lymphocytic infiltration. In the case of abscesses there is a large infiltration of lymphocytes and neutrophils. Later lesions show thickening and fibrosis of the duct walls and small focal fat necrosis around the ducts, accompanied by a large number of histiocytic and lymphocytic infiltrates, mainly plasma cells. Treatment For plasmacytoid mastitis, neither purely Western surgical treatment is advocated, nor should we be conservative and aggravate the disease, but should give full play to the respective advantages of Chinese medicine and Western medicine to shorten the course of the disease and reduce recurrence. Western medicine considers surgery to be an effective treatment for this disease. After the location of the diseased ducts is clarified, the dilated ducts can be removed along with the surrounding breast tissue, but there are many problems with surgical treatment, such as a high recurrence rate, leading to multiple surgeries, which seriously damages the appearance of the breast and causes both psychological and physical trauma to the patient. For abscesses and fistulas, Chinese medicine treatment is based on the identification of evidence and the combination of internal and external treatment. For abscesses and fistulas, Chinese medicine treatment such as incision, hanging, dragging and topical application of decay and muscle-building drugs are used, which have the advantages of less damage to the appearance of the breast, good healing and less recurrence, and are more acceptable to patients compared to Western medicine surgical excision.