TITLE:
Unmasking the Unusual: Cystic Neutrophilic Granulomatous Mastitis (CNGM) in a Young Woman
AUTHORS:
Twisha Oza, Brittany Upadhyay, Keyvona Moultrie, Ashley Hendrix
KEYWORDS:
CNGM (Cystic Neutrophilic Granulomatous Mastitis), Histology, Corynebacterium Kroppenstedtii, Pregnancy
JOURNAL NAME:
Case Reports in Clinical Medicine,
Vol.15 No.10,
October
9,
2026
ABSTRACT: Cystic neutrophilic granulomatous mastitis (CNGM) is a distinctive histopathologic subtype of granulomatous mastitis characterized by lobulocentric granulomas with cystic lipid spaces rimmed by neutrophils. There is a strong association with Corynebacterium kroppenstedtii, a fastidious, lipophilic Gram-positive bacillus with tropism for breast tissue. Here we report a case of granulomatous mastitis occurring during pregnancy, emphasizing the diagnostic importance of recognizing the characteristic histologic pattern of CNGM. This case highlights the critical role of the breast pathologist in establishing a specific diagnosis when pregnancy-associated breast changes complicate clinical and radiographic interpretation and therapeutic options are necessarily constrained.