Combining intralesional steroid injection with oral steroids in patients with idiopathic granulomatous mastitis

Idiopathic granulomatous mastitis (IGM) is a chronic inflammatory breast disease. Currently, there is no international standard for steroid use in IGM, particularly for intralesional steroid injections. This study aimed to determine whether patients with IGM who received oral steroids could benefit from intralesional steroid injection. We analyzed 62 patients with IGM whose main clinical presentation was mastitis masses and who received preoperative steroid therapy. Group A (n = 34) received combined steroid treatment: oral steroids (starting dose, 0.25 mg/kg/d; tapered off) and intralesional steroid injection (20 mg per session). Group B (n = 28) received oral steroids only (starting dose, 0.5 mg/kg/d; tapered off). Both groups underwent lumpectomy at the end of steroid treatment. We analyzed the preoperative treatment time, preoperative mass maximum diameter reduction rate, side effects, postoperative satisfaction, and rate of IGM recurrence. The mean age of the 62 participants was 33.6 ± 2.3 (range, 26-46) years, and all had unilateral disease. We found that oral steroids combined with intralesional steroid injection yielded better therapeutic effects than did oral steroids alone. The median maximum diameter reduction of the breast mass was 52.06% in group A and 30.00% in group B (P = .002). Moreover, the use of intralesional steroids reduced the duration of oral steroid use; the median durations of preoperative steroid therapy were 4 and 7 weeks in groups A and B, respectively (P < .001). Group A patients were more satisfied (P = .035) with the postoperative results, including postoperative appearance and function. No statistically significant between-group differences were noted regarding side effects and recurrence rates. Preoperative administration of oral steroids combined with intralesional steroid injection yielded better therapeutic effects than did oral steroids alone and may be an effective future treatment for IGM.