Plasmacytoid mastitis, also called ductal dilatation, is called acantholytic canker sore in Chinese medicine, commonly known as ductitis, or plasmacytosis for short. Plasma milk is not caused by bacterial infection, but by the accumulation and overflow of fatty material in the ducts, causing chemical irritation and immune response around the ducts, resulting in a large number of plasma cell infiltrates, hence the name plasma cell mastitis. Repeated episodes and fistulas are formed after rupture, which can be followed by bacterial infections that do not heal for a long time. Therefore, it is a special kind of mastitis. Plasmacytoid mastitis occurs mostly in middle-aged and older women, with a peak age of 50 to 60 years, and most patients have nipple invagination deformity. The accumulation of lipid-laden secretions in the large milk ducts under the nipple and areola causes dilation of the milk ducts, and later the accumulation decomposes and produces chemicals that continuously irritate the surrounding tissues, causing inflammation. Sometimes the inflammation may become acute and become an abscess, so the pus is often filled with bean curd-like or powder-like material, which is why Chinese medicine calls it “acne canker sores”. Many people do not recognize this disease and mistake it for a common bacterial infection, or misdiagnose it as breast tuberculosis, or worst of all, misdiagnose it as breast cancer and cut the breast. The clinical manifestations of plasmacytoid mastitis are sudden onset and rapid development. The lesions are mainly located in the areola, and live like the extension of the Moi quadrant, feeling localized pain and discomfort in the breast, and can be palpable lumps, which are hard and tough. The surface is nodule-like with poorly defined boundaries and no adhesions to the chest wall. In some cases, the skin of the breast is edematous and orange peel-like, and there are usually no systemic symptoms such as fever. The nipples are often edematous and orange peel-like, usually without fever and other systemic symptoms. The nipples often secrete powder-like material with a foul odor. A small number of patients have nipple discharge, which is bloody or watery, and may be accompanied by enlargement of the axillary lymph nodes on the affected side. In the late stage, the lump becomes softened and forms an abscess. The abscess breaks down and flows pus mixed with powder-like pus and causes fistulas in the areola, resulting in recurrent wounds and scarring, which causes the nipple to sink into a concave position. The clinical manifestations of plasmacytoid mastitis are varied, with some patients exhibiting long-term nipple discharge, or nipple invagination alone, or localized lumps that persist for years. The clinical features are as follows: 1. It is not related to pregnancy and lactation, i.e., it does not develop during lactation. 2. Most patients are associated with various malformations of the nipple or dilated ducts. 3. There are many young women and many unmarried ones. 4. Recurrent, long-lasting paramametrial fistulas or chronic inflammatory masses. There is a case with a history of up to 13 years. 5, This disease is not uncommon, accounting for about 10% of breast patients. The first thing you need to do is to take a look at the actual results. The more you use cold medicine, the less the lumps will disappear. 2. In the chronic stage, warming medicine is used – Yang He Tang plus or minus. 3. The best time to operate is during the interictal period, i.e. the wound healing period, but some people think that what surgery is done when the disease is well? Wait until the redness and swelling again, break down, so delayed a long time. If the wound can not heal, to wait for the acute inflammation to subside, the most superficial wound when surgery, this time there is the possibility of infection after surgery. 4, The key to successful surgery is to flip the areola, remove the lesion thoroughly and clean all traumatic surfaces. 5, the technical key to the surgery is to maintain the perfection of the shape and the necessity to do the plastic surgery of nipple entropion. The treatment depends on the different clinical manifestations, but the main point of treatment is the surgical removal of the diseased breast ducts in order to achieve complete eradication. If there is an abscess, an incision is made to drain the abscess, and if there is a fistula, the fistula is removed. In some cases, simple mastectomy may be considered for most chronic fistulas or severe breast deformities that are too long in duration. Plasmacytoid mastitis is easily confused with non-lactating septic mastitis and breast tuberculosis, especially when the tuberculosis breaks down and forms a fistula. When there is nipple invagination combined with a lump, it can be easily confused with breast cancer, so local biopsy is often needed to differentiate.