Granulomatous mastitis is caused by aseptic inflammation and is not a tumor, nor is it benign or malignant. Granulomatous mastitis is a chronic inflammatory disease of the breast with granuloma formation of the breast tissue as the main pathological manifestation. Usually, the inflammation invades the lobules of the breast and causes granulomas to appear in the breast tissue, causing the patient to develop granulomatous mastitis, which is a non-lactating mastitis. This disease is caused by aseptic inflammation and is not a tumor, but is mainly characterized by painful lumps in the breast, hard texture. When the disease worsens, the lump may increase in size for a short period of time, and after a few days, there may be obvious inflammatory changes, localized redness, swelling, heat and pain, and abscesses may be formed. Therefore, this disease is not a benign tumor. Granulomatous mastitis secondary infection can be treated with antibiotics such as amoxicillin and levofloxacin under the guidance of a doctor, and when the symptoms are severe, it can be treated with hormones and other drugs. If the symptoms are not relieved by medication, the lesion can be removed by surgery. Patients with granulomatous mastitis should seek treatment at a regular hospital to avoid aggravation of the condition.