The occurrence of plasmacytic mastitis may be related to the functional state of the mammary gland and endocrine disorders. The main etiological factors are as follows: congenital nipple deformity, depression, uncleanliness, or obstruction of the milk ducts by fibers on the undergarments; a history of mastitis or trauma to the breast, which destroys the milk ducts; together with ageing, reduced ovarian function, decreased estrogen levels, irregular proliferation of the epithelium of the milk ducts, malfunction of secretion, accumulation of large amounts of lipid secretions in the nipples and surrounding milk ducts, dilation of the milk ducts, accumulation of The secretion decomposition chemical products stimulate the local tissues, the products of which can exude from the ducts and an inflammatory disease with a predominantly plasma cell infiltration occurs. Clinical features of plasmacytoid mastitis: 1. Age of predilection: The disease is most often seen in non-lactating women aged 30-50 years, with a slow onset and may have an acute phase or a course of monstrous episodes. 2, clinical manifestations: breast pain or subareolar lumps, lumps are hard or tough, the surface is mostly smooth. Sometimes the skin is red and swollen and painful to touch. The nipple is discharged with powder-like material and smells foul. In later stages, aseptic abscesses may form, forming multiple sinus tracts or fistulas. The ipsilateral axillary lymph nodes may be enlarged. Clinical typing of plasmacytoid mastitis: 1. Occult type: overflow as the main symptom, accompanied by breast swelling or slight tenderness, and nipple depression. 2. Lump type: The main symptom is a nipple lump (mostly located around the areola), accompanied by mild pain and pressure discomfort. 3. Abscess type: an abscess is formed on the basis of a lump secondary to acute infection, and the lesion is mostly located under the areola, mostly accompanied by a breast fistula. 4.Fistula type: the abscess breaks down by itself or the fistula left after incision and drainage, which does not heal for a long time.