Inflammatory granulomatous mastitis caused by Corynebacterium kroppenstedtii: A clinical challenge

• Published in: Clinical infection in practice Vol. 15; p. 100147
• Main Authors: Brouwer de Koning, I.M., Lemson, A., Renders, N.H.M., Bessems, M., Nooijen, P.T.G.A., Draaisma, W.A., Bosscha, K.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-07-2022; Elsevier
• Subjects: Antibacterial agent; Corynebacterium; Diagnostic techniques and procedures; Mastitis; Mastitis; Corynebacterium; Diagnostic techniques and procedures; Antibacterial agent
• ISSN: 2590-1702; 2590-1702
• DOI: 10.1016/j.clinpr.2022.100147

•It is important to rule out a malignancy as soon as possible in case of mastitis.•The diagnostic process of Corynebacterium kroppenstedtii is a real challenge.•Anaerobe culturing should be added to the standard diagnostic procedure in mastitis.
Corynebacterium induced granulomatous mastitis is a rare inflammatory condition of the breast, generally occurring in parous reproductive-aged women, that could simulate inflammatory breast cancer. Therefore, it is important to rule out the diagnosis of cancer because treatment consists of long-term antibiotics or, in case of clinical deterioration, surgical procedures. However, excluding a malignancy and determining a Corynebacterium induced mastitis is a diagnostic challenge.
Three patients with mastitis caused by Corynebacterium kroppenstedtii were described: a patient with a unilateral painful mass with abscess formation later, a patient with recurrent mastitis for months with a sudden progression and a patient with persisting mastitis despite antibiotic treatment.
Preoperative imaging reduced the possibility of, but was unable to exclude, a malignancy. Multiple and/or deep biopsies were needed to confirm granulomatous mastitis and extensive staining was needed to find Corynebacterium kroppenstedtii.
Because clinical and/or radiological features are insufficient to prove Corynebacterium induced granulomatous mastitis, core-needle or surgical biopsies remain the cornerstone of the diagnosis together with extensive (beyond Gram) staining looking for Corynebacterium subspecies.