Cystic Neutrophilic Granulomatous Mastitis: Imaging Features With Histopathologic Correlation.

This article focuses on cystic neutrophilic granulomatous mastitis (CNGM), a rare subtype of granulomatous lobular mastitis (GLM) characterized histologically by suppurative lipogranulomas—lipid vacuoles rimmed by neutrophils and epithelioid histiocytes—often associated with Corynebacterium kroppenstedtii infection. Imaging findings of CNGM, including mammographic asymmetries and irregular masses and sonographic irregular hypoechoic masses or abscesses, are nonspecific and overlap with benign and malignant breast conditions, necessitating biopsy for diagnosis. Identification of the causative organism requires specialized microbiological techniques such as extended culture, Gram staining, and molecular analysis due to the difficulty in detecting Corynebacterium. Treatment options vary and include antibiotics, steroids, and surgery, but no consensus exists on optimal management, and recurrence is common. Emerging evidence suggests that CNGM and GLM may represent different stages of the same disease process, highlighting the need for further research to improve diagnosis and treatment.