Corynebacterium kroppenstedtii: a challenging culprit in breast abscesses and granulomatous mastitis

PURPOSE OF REVIEW: Corynebacterium kroppenstedtii is a difficult pathogen associated with granulomatous mastitis and recurrent breast abscesses. Despite over a dozen studies, there is no guidance on surgical interventions, steroid use, or dosing or duration of antibiotic treatment. RECENT FINDINGS: Initially seen in predominantly Maori and Pacific Islander multiparous, postlactating women, C. kroppenstedtii breast infection has since been reported throughout the world, including in nulliparous women. Additionally, emerging data suggest that hyperprolactinemia is a modifiable risk factor for these infections. This article reviews a patient case and data from 87 other cases to compile current best practices for diagnosis, treatment, and monitoring, and provides areas for future study. SUMMARY: In cases of granulomatous mastitis and breast abscess, especially if recurrent, infection with C. kroppenstedtii should be considered. Microbiologists should be alerted to the specialized growth conditions and tools needed for appropriate culturing, identification, and antibiotic susceptibility testing. Clinicians should utilize a multimodal approach with surgical and antibiotic treatment to maximize clinical cure and reduce recurrence.