Pin Wang, Quanling Ou, Ling Li, Ying Liu, Jian Wu
GMENA syndrome is a distinct clinical subtype of IGM characterized by acute onset, more severe breast involvement, rapid initial response to glucocorticoids, and, after an adequate prolonged course, favorable long-term outcomes with low recurrence. Early recognition and a treatment strategy of prompt initiation followed by sufficient consolidation are recommended to avoid unnecessary surgery.
BACKGROUND: GMENA syndrome (granulomatous mastitis, erythema nodosum, with or without arthritis syndrome) is a rare subtype of idiopathic granulomatous mastitis (IGM). However, large cohort studies systematically evaluating its clinical features, response to glucocorticoid therapy, and prognosis are lacking.
METHODS: This single-center retrospective cohort study included 201 patients diagnosed with IGM at the Third People's Hospital of Chengdu between January 2014 and January 2026. Among them, 20 patients presented with GMENA syndrome (GMENA group) and the remaining 181 served as the control group. Demographic characteristics, lesion features, laboratory findings, and treatment outcomes were collected for both groups. The two groups were compared regarding glucocorticoid treatment response (early improvement and total treatment duration) and recurrence rate.
RESULTS: Compared with the control group, GMENA patients were younger at onset (31-40 years: 80.0% vs. 49.7%, p = 0.01) and had a shorter interval from symptom onset to presentation (85.0% vs. 23.8% presenting within 9 days, p < 0.01). They also exhibited more extensive disease: multiquadrant involvement (100.0% vs. 14.4%), mass size > 3 cm (100.0% vs. 74.0%), multifocal lesions (100.0% vs. 18.8%), and subcutaneous abscess (60.0% vs. 15.5%) (all p < 0.01). All GMENA patients had unilateral involvement. The GMENA group showed a early improvement to glucocorticoids (significant improvement within 1 week: 75.0% vs. 34.8%, p < 0.01), but required a longer treatment duration (>6 months: 65.0% vs. 8.8%, p < 0.01) and had a significantly lower recurrence rate (5.0% vs. 33.7%, p < 0.01). Autoantibody panels were negative in both groups, and no significant difference was found in pus culture positivity rates.
CONCLUSION: GMENA syndrome is a distinct clinical subtype of IGM characterized by acute onset, more severe breast involvement, rapid initial response to glucocorticoids, and, after an adequate prolonged course, favorable long-term outcomes with low recurrence. Early recognition and a treatment strategy of prompt initiation followed by sufficient consolidation are recommended to avoid unnecessary surgery.