Cystic Neutrophilic Granulomatous Mastitis: A Case Series.

Cystic neutrophilic granulomatous mastitis (CNGM) is a distinct histopathological subtype of granulomatous mastitis that commonly presents as an inflammatory breast lesion in women of reproductive age. We present a retrospective case series of five parous women who presented with unilateral breast lumps between 2023 and 2025. Histopathological examination revealed classical features of CNGM in all cases. Microbiological culture yielded various isolates, including Corynebacterium tuberculostearicum, Tsukamurella species, and Mycolicibacterium fortuitum complex, while two cases showed no growth. The findings highlight a heterogeneous microbial spectrum in CNGM and emphasize the importance of microbiological evaluation for accurate diagnosis and appropriate antimicrobial therapy.