Clinical features of cystic neutrophil granulomatous mastitis in 62 cases

Background: Cystic Neutrophilic Granulomatous Mastitis (CNGM) is a rare inflammatory condition affecting the breast. Despite its rarity, understanding its pathogenesis and clinical features is crucial for accurate diagnosis and effective management. This study delves into the nuanced aspects of CNGM, shedding light on its unique characteristics and potential underlying mechanisms. Methods: In this meticulous investigation, we meticulously examined and analyzed the biological data, clinical features, ultrasound imaging findings, and histopathological morphological information of 62 patients diagnosed with CNGM after thorough pathological examination. The study cohort was sourced from the Galactophore department of Beijing Hospital of Traditional Chinese Medicine, spanning the period from September 2019 to September 2022. Results: Sixty-two patients, with an average age of 33.30 years, were predominantly female. Among the 52 patients with detailed documentation of onset following the final delivery, various factors were identified, including hyperprolactinemia, pituitary tumors, psychiatric medication history, granulomatous mastitis history, breast trauma history, and a family history of breast cancer. The primary clinical manifestations were characterized by pain and palpable masses, accompanied by localized symptoms such as redness, ulceration, nipple discharge, and nipple retraction. Additionally, systemic symptoms, such as fever, headache, erythema nodosum, and cough, were observed. Ultrasound examinations revealed predominantly hypoechoic masses with heterogeneous echogenicity. Axillary lymphadenopathy, dilated ducts, and thickening of breast tissue were also noted in some cases. Histopathological analyses demonstrated lobular structural destruction, acute and chronic inflammatory cell infiltration, multinucleated giant cell reactions, granulomas, and cyst formation. Gram staining revealed detection rates of 41.94% (26/62) for gram-positive bacteria and 11.29% (7/62) for gram-negative bacteria.  Conclusion: This study highlights the occurrence of Chronic Nonspecific Granulomatous Mastitis (CNGM) in women of childbearing age. Factors such as milk stasis, mammary duct secretion overcharge, exogenous trauma, hormonal influences, and bacterial colonization are implicated in the initiation and recurrence of CNGM. Notably, nipple retraction emerged not only as a clinical symptom but also as a potential risk factor for CNGM. The prevalence of multiple hypoechoic regions in CNGM surpassed that observed in breast cancer cases. The detection of gram-positive bacteria underscores the pivotal role of bacterial infections in the development of CNGM. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was partially funded by Gansu Provincial Science and Technology Program Subsidized Projects (21JRIRG303); Research and Transformation of Clinical Diagnosis and Treatment Technology in Beijing (Z211100002921020); Young Doctor Scholar Project (2022); National Administration of Traditional Chinese Medicine (GZY-KJS-2022-035); Beijing Traditional Chinese Medicine Science and Technology Development Fund Project (BJZYQN-2023-08). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This study was approved by the Medical Ethical Committee of Beijing Hospital of Traditional Chinese Medicine (2023BL02-054-01). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present work are contained in the manuscript