Abstract
Objective:Cystic neutrophilic granulomatous mastitis(CNGM)is a rare histological subtype of granulomatous lobular mastitis(GLM).Its diagnosis relies on a characteristic pathological morphology,namely cystic spaces surrounded by neutrophils within granulomas.The lesion is often associated with Corynebacterium infection.However,compared with conventional GLM,its distinctive clinicopathological spectrum has not been systematically defined through larger-sample case-control studies.This study aims to clarify the disease characteristics of CNGM by comparing differences in clinical manifestations,pathological features,bacteriological findings,treatment response,and prognosis between patients with CNGM and those with non-CNGM GLM,thereby providing evidence-based support for precise clinical identification and individualized treatment.
Methods:A retrospective case-control study design was adopted.All cases pathologically diagnosed with GLM in 2019 at the Department of Breast Surgery,Beijing Hospital of Traditional Chinese Medicine,Capital Medical University were included.Hematoxylin and eosin(HE)-stained sections of all cases were reviewed independently by 2 senior pathologists.According to the presence or absence of the key morphological feature"cystic spaces surrounded by neutrophils within granulomas",all GLM cases were divided into 2 groups:the CNGM group and the non-CNGM GLM control group.Demographic data(age,reproductive history,breastfeeding history),clinical characteristics(time of onset,lesion laterality,lesion size,clinical stage,skin involvement,accompanying symptoms),bacteriological findings(Gram-stain bacterial positivity rate),pathological descriptions,treatment regimens,and prognostic information(time to clinical remission and recurrence rate)were collected for both groups.Data were analyzed using SPSS 20.0 software.Continuous variables with normal distribution were compared using the independent-samples t test,and non-normally distributed variables were compared using Mann-Whitney U test.Categorical variables were compared using the chi-square test or Fisher's exact test.Bonferroni correction was applied for multiple comparisons.
Results:A total of 158 patients with GLM were included,among whom 56 cases(35.4%)were classified into the CNGM group due to the presence of characteristic pathological changes,and the remaining 102 cases formed the GLM control group.No significant differences were observed between the 2 groups in baseline demographic characteristics such as mean age,lesion laterality,interval since last childbirth,and duration of breastfeeding(all P>0.05).However,the median time from onset to presentation in the CNGM group was significantly shorter than that in the GLM group(2.5 weeks vs 6.0 weeks,P=0.001),suggesting more rapid disease progression.Regarding lesion characteristics,there were no statistically significant differences between the two groups in maximum lesion diameter,distribution of clinical stages,or the proportion of lesions larger than 10 cm(all P>0.05).However,the proportion of skin involvement was lower in the CNGM group than in the GLM group(32.1%vs 48.0%);although this did not reach the corrected significance threshold,it still suggested potential differences in the pattern of inflammatory spread.Bacteriological findings showed that the bacterial detection rate on HE-stained sections in the CNGM group was as high as 44.6%,significantly higher than that in the GLM group(2.9%,P<0.001).Gram staining revealed positive bacilli within cystic spaces only in the CNGM group(41/56 cases,73.2%),while none were detected in the GLM group,and the difference was statistically significant(P<0.001).No significant differences were observed between the two groups regarding accompanying symptoms,triggering factors,or axillary lymphadenopathy.Treatment and prognosis analysis showed that patients in both groups received traditional Chinese medicine-based therapy centered on in-hospital preparations,and there were no statistically significant differences in time to clinical remission(P>0.05).
Conclusion:This study confirms that CNGM is a distinct subtype of GLM.Its core feature is the morphology of"neutrophil-surrounded cystic granulomas",which is highly associated with Gram-positive bacillary infection(especially Corynebacterium).Clinically,it is characterized by acute onset,rapid disease progression,and a low proportion of skin involvement.The study demonstrates the feasibility of diagnosing CNGM based on histomorphology,and thicker sections and repeated staining can significantly improve the detection rate of Corynebacterium.Etiological implications suggest that CNGM may benefit more from combined anti-infective therapy,whereas conventional GLM may focus on immune regulation.Precise classification is therefore of important value for pathological diagnosis and individualized management of GLM.关键词
肉芽肿性乳腺炎/克氏棒状杆菌感染/中性粒细胞/肉芽肿/乳腺疾病/病例对照研究/预后Key words
granulomatous mastitis/Corynebacterium kroppenstedtii infection/neutrophils/granuloma/breast diseases/case-control study/prognosis分类
医药卫生
