Objective:To investigate the etiology, clinical manifestations, clinicopathological features of cystic neutrophil granulomatous mastitis (CNGM).Methods:From Jan 2019 to Dec 2020, 95 CNGM cases diagnosed by biopsy pathology at Chongqing Hospital of Traditional Chinese Medicine and Chongqing Liangping District Hospitol of Traditional Chinese Medicine were reviewed.Results:There were 95 female patients, aged 21 to 50 years, with a median age of 32 years. Laboratory examination showed that 56% (53/95) cases had elevated rheumatoid antibody level, 27 % (26/95) had increased level of serum thyroid antibody, 15% (14/95) had elevated antineutrophil antibody, 35% (33/95) had increased ESR, 38% (36/95) had increased C-reactive protein. The positive rate of Gram-stained bacilli was 82% (78/95). Histology: pyogenic granuloma with lobule of breast as the center, the center of granuloma was cystic vacuole.Immunohistochemistry showed that the inflammatory cells in and around granuloma were mainly CD3 + cells, and CD4 + cells were more than CD8 + cells. Conclusions:The cystic neutrophilie granulo matous mastitis is a rare type of idiopathic granulomatous mastitis. The diagnosis of CNGM is dependent on its specific pathological features.