The exact factors responsible for the development of the disease are still unclear. It has been suggested that it is related to the patient’s use of contraceptive medications, but most reports in the literature indicate that contraceptive use is not the primary cause of the disease. It has also been suggested that the disease is associated with infection, but there is no evidence of bacteriologic pathogenesis, and in the treatment of the disease, antibiotics do not completely cure the lesion, although they may provide transient relief of pain in some patients, suggesting that the bacterial infection is likely secondary. Most patients are post-lactating women, some with a clear history of lactation, and the majority of patients develop the disease within 6 years after delivery, with a median age of onset of 3 years, suggesting that lactation may be the underlying cause of the disease. The disease can be triggered by trauma. The use of corticosteroids can rapidly limit the lesions and relieve the symptoms, suggesting that the development of the disease is related to autoimmune factors. The possible pathogenesis of the disease is that the patient’s milk stagnates in the mammary gland alveoli for various reasons, the long-term stagnation of milk proteins continuously precipitates lipids, the integrity of the glandular alveoli or duct wall is destroyed under external force or infection, the stagnation breaks into the mammary interstitium as chemicals, inducing an inflammatory reaction, which further destroys the surrounding normal milk ducts, leading to more stagnation into the interstitium, thus forming a vicious cycle The inflammatory response further destroys the surrounding normal milk ducts, leading to more sludge into the mass, thus creating a vicious cycle that leads to rapid enlargement of the mass. The differential diagnosis of granulomatous mastitis: granulomatous mastitis occurs in menstruating women of childbearing age with a history of lactation and develops during the non-lactation period. Some patients have a history of trauma, infection, or use of female hormonal medications. It often occurs unilaterally in the breast, but can also occur bilaterally or at different times. The lesion is located in the peripheral part of the breast, most often in the upper quadrant, and the lump may involve the entire breast in large cases. Initially, the lump is painless or slightly painful, the skin is not red or slightly red, the lump is hard, and it is rarely accompanied by systemic symptoms such as chills and fever. As the disease progresses, the lump may increase rapidly, involving multiple quadrants, with unclear borders and an unsmooth surface, and may adhere to the skin or surrounding tissues, with local skin redness and pain, accompanied by enlarged ipsilateral axillary lymph nodes, and a few with fever; if not treated in a timely manner, breast abscesses may appear, breaking down and flowing pus, forming sinus tracts that do not heal over time. Breast ultrasound and mammogram are not specific, and the lump phase is easily confused with breast cancer; coarse needle aspiration biopsy can help in differential diagnosis. Plasmacytoid mastitis has many similarities with granulomatous mastitis, such as the clinical manifestations of chronic mastitis, which occurs in non-lactating women and can present with symptoms such as lumps, abscesses, and sinus tracts, but the causes of the two are different and the clinical manifestations are different. Most patients with plasmacytoid mastitis have a history of nipple invagination; the lesions mainly involve the large ducts of the nipple and areola, so the lesions are located in the nipple-areola area; nipple discharge is common and is plagioid or purulent, and may be accompanied by acne-like discharge; the mass is red, swollen and painful, and the pus is interspersed with lipid-like material after rupture, which is often recurrent and can form fistulas, often communicating with the milk ducts; ultrasound shows hypoechoic mass shadows and dilated ducts of the breast; pathological sections show dilated large ducts. Pathological sectioning reveals large dilated ducts and periductal plasma cell infiltration. Because some patients have secondary bacterial infections, anti-infective treatment at the beginning of the disease may result in transient remission. Because of the multifocal nature of the lesions, it is difficult to cure the disease by complete drainage. Combined corticosteroid kinase therapy at the beginning of the disease may result in early lesions that are less extensive. Preoperative trial of adrenocorticosteroid therapy can shorten the course of treatment and reduce the scope of surgery. Patients with acute inflammatory infections can use antibiotics during the perioperative period, which can reduce pain and effectively control inflammatory infections, creating good conditions for surgical excision of lesions and wound healing. In his clinical practice for many years, Prof. Lin Yi founded the comprehensive therapy of “removing pus and decay” based on the theory of “removing decay and regenerating muscle”, using various external treatments such as fire-needle hole branding, pus lifting and drug twisting drainage, scraping, twisting decay, cotton bandage, and Chinese herbal compresses in parallel. The treatment is characterized by the use of traditional Chinese medicine and is supplemented by the internal use of Chinese herbal medicines to soften and disperse the hard knots, to help eliminate toxins and carbuncles, and to benefit the qi and the ying. This method was used to treat 12 patients, 11 were clinically cured and 1 was improved, with a cure rate of 91.7% and an average duration of 51.72±19.05 days, with little trauma, little postoperative breast deformation, and no recurrence during the follow-up period of 1 month to 21 months. Our department has accumulated some clinical experience in the surgical treatment of granulomatous mastitis. In recent years, a total of 28 patients with granulomatous mastitis were treated surgically, of which 25 cases had one-stage healing of the incision after surgery and 3 cases had two-stage healing, and no recurrence was found in the postoperative follow-up period of 6 months to 23 months. Experience: Most lesions of granulomatous mastitis are widespread, and lesions are often isolated, with normal glands separating them, and can be unconnected. Some lesions are relatively insidious and difficult to detect even by preoperative ultrasound. If the underlying lesions are not detected, there is a greater risk of recurrence after surgery. Sometimes it is important to weigh the pros and cons between preserving the gland and recurrence of the disease, and to try to maintain a good breast appearance while curing the disease. As for which patients are suitable for surgery, the patient’s wishes are the most important. The following two points can be taken into consideration: first, those who cannot insist on repeated scratching for fear of pain; second, those who have extensive lesions with poor results from external Chinese medical treatment methods.