Clinical characteristics and therapeutic strategy of Granulomatous mastitis accompanied by Corynebacterium kroppenstedtii —— a retrospective cohort study

Abstract

Abstract Background: More and more evidences have suggested that Corynebacterium kroppenstedtii is associated with some cases of granulomatous mastitis, mostly based on pathology or microbiology. We aimed to find the clinical characteristics and treatment regimens for granulomatous mastitis with Corynebacterium kroppenstedtii infection. Understanding these clinical features is essential for patient care. Methods: We retrospectively collected 201 patients who were diagnosed as granulomatous mastitis pathologically and had microbiological results either Corynebacterium kroppenstedtii or no bacterial growth, recorded and analyzed their demographics and clinical characteristics, clinical outcome. Results: There were 107 patients in CK group, 94 patients in negative group. Sinus formation (x2=13.028, p=0.000), time to complete remission at the first treatment periods (Z=-3.027, p=0.002), diameter of breast mass at first-time medical consultancy (Z=-2.539, p=0.011) and recurrence (x2=4.953, p=0.026) were statistically significant. Age (Z=-1.046, p=0.295), laterality (x2=4.217, p=0.121), delivery way (x2=0.098, p=0.755), time to presentation since last delivery (x2=0.028, p=0.868), BMI (Z=-0.947, p=0.344), lactating time (Z=-1.378, p=0.168), parity (x2=1.799, p=0.180), gravida (Z=-0.144, p=0.885), history of lactational mastitis or abscess (x2=0.115, p=0.734), local trauma (x2=0.982, p=0.322), hyperprolactinemia (x2=0.706, p=0.401), erythema nodosum (x2=0.292, p=0.589), nipple discharge (x2=0.281, p=0.596) did not demonstrate a statistically significance. As to recurrence related to therapeutic strategy, except for surgery combined with immunosuppressants (x2=9.110, p=0.003) was statistically significant, none of the other treatment regimens reached statistical significance. Recurrence rate of patients in CK group using rifampicin in their treatment course was 22.0% (x2=4.892, p=0.027). Conclusions: Granulomatous mastitis accompanied by Corynebacterium kroppenstedtii is easier to form sinus and has higher recurrence rate. Both of the clinical characteristics may prove Corynebacterium kroppenstedtii plays an important role in the development and progression of granulomatous mastitis. Lipophilic antibiotics may be essential for GM with Corynebacterium kroppenstedtii infection.