Granulomatous mastitis surgery for 10 days and hard lumps may be caused by postoperative breast scar tissue, recurrence of granulomatous mastitis and incomplete surgery. 1. Post-surgical scar tissue of granulomatous mastitis: Post-surgical scar tissue of granulomatous mastitis may be the result of poor alignment of the wound when doing the surgery, and there is a large space between the wound and the wound, which may result in the formation of wound scarring due to the appearance of granulation and scar healing. You can follow the doctor’s instructions to use injectable drugs can promote the scar recovery, such as tretinoin and so on. 2. Recurrence of granulomatous mastitis: In case of recurrence of granulomatous mastitis, another surgery may be needed to remove the localized inflammatory mass. 3. Incomplete surgery: Incomplete surgery of granulomatous mastitis leads to residual pus cavity, there will be a localized hard lump that does not disappear, further exploration is needed, and if necessary, another surgery is needed to remove the hard lump. It is recommended that the patient regularly review, actively cooperate with the doctor’s treatment, and in the doctor’s guidance for the use of medication, not unauthorized use of medication, to avoid the emergence of adverse consequences.