Ultrasound-guided microwave ablation versus conventional surgery for Granulomatous Lobular Mastitis: A two-center retrospective comparative stud

BACKGROUND: Granulomatous lobular mastitis (GLM) is a chronic inflammatory breast disease that causes substantial pain, cosmetic deformity, and psychosocial distress. Evidence directly comparing ultrasound-guided microwave ablation (MWA) with conventional surgery (CS) remains limited. METHODS: We conducted a two-center retrospective cohort study of consecutive women with core needle biopsy-confirmed GLM treated between March 2020 and February 2025. Treatment allocation was non-random and reflected routine clinical decision-making. The primary outcomes were overall cure and recurrence. Secondary outcomes included perioperative resource utilization and patient-reported outcomes assessed with a BREAST-Q domain-based questionnaire adapted for GLM follow-up. Baseline balance was described with both P values and standardized mean differences (SMDs). RESULTS: Among 233 patients (MWA, n = 102; CS, n = 131), overall cure was achieved in 97.06% and 96.18% of patients, respectively (risk difference, 0.88 percentage points; 95% CI, -3.76 to 5.51; P = 1.000). Recurrence occurred in 4.90% of the MWA group and 3.82% of the CS group (risk difference, 1.09 percentage points; 95% CI, -4.24 to 6.41; P = 0.751) during a median follow-up of 18.5 months. Compared with CS, MWA was associated with lower estimated blood loss, shorter procedure time, lower postoperative drainage burden, and shorter hospitalization (all P < 0.001), while total hospitalization cost did not differ significantly. Questionnaire scores favored MWA for sexual well-being, breast satisfaction, and scar satisfaction, whereas psychological well-being, chest physical well-being, and satisfaction with the medical team were similar between groups. SMDs indicated some baseline imbalance, particularly for multiple-quadrant involvement and ultrasound lesion size. CONCLUSIONS: In this retrospective observational comparison, MWA and CS were associated with similarly high cure rates and low recurrence. MWA was additionally associated with lower perioperative burden and better breast- and scar-related satisfaction. Prospective studies with standardized co-interventions, confounding adjustment, and validated patient-reported outcome assessment are warranted.