New Findings on Autoimmune Etiology of Idiopathic Granulomatous Mastitis: Serum IL-17, IL-22 and IL-23 Levels of Patients

Breastfeeding and secretory factors in idiopathic granulomatous mastitis: Unveiling etiological insights

BACKGROUND

Idiopathic granulomatous mastitis (IGM) is a rare, chronic inflammatory, and benign breast disease. Its unclear etiology may involve autoimmune reactions, secretion-related factors, and microorganisms.

AIM

To analyze data from our IGM patient series and compare potential etiological factors.

METHODS

We prospectively collected data using follow-up forms for patients diagnosed with IGM at our breast clinic from September 2014 to December 2020 and analyzed it retrospectively.

RESULTS

The study cohort included 220 patients, with a median age of 34 years (range: 20-58). A majority, 217 patients (98.6%), reported a history of breastfeeding, with a median duration of 36 months (range: 0-156). The median interval between the last breastfeeding session and disease onset was 25 (25th-75th percentiles: 15-44) months. Additionally, 116 patients (53.5%) reported breastfeeding-related problems. In 41 surgical patients, dense milky-brown debris in the breast ducts was noted. Although no independent seasonal fluctuations in disease onset were detected, a reduction in IGM cases during the summer months was found to correlate with a general decrease in all breast clinic visits.

CONCLUSION

Most patients reported recent breastfeeding and half experienced related problems, supporting the secretion theory's relevance in IGM's etiology. The absence of seasonal fluctuations suggests that secretion-related factors may be more central to IGM development than autoimmunity or infections. These findings offer crucial insights for future research into IGM's complex causes.

Immune regulation: a new strategy for traditional Chinese medicine-based treatment of granulomatous lobular mastitis

Granulomatous lobular mastitis (GLM) presents significant challenges, including high rates of morbidity, recurrence, and disability, ultimately impacting women's health and quality of life. Local autoimmune imbalance involving dysregulated cytokines and immune cells has been recognized to play a key role in the pathology of GLM. Traditional Chinese medicine (TCM), with its multi-component, multi-pathway and multi-target characteristics, offers unique advantages and broad prospects in the treatment of GLM. Here, we review the relationship between immune dysregulation and GLM, as well as the regulatory mechanisms of TCM-based interventions, with the aim of providing new insights and foundational knowledge for the clinical treatment of GLM, while promoting the further application and development of TCM-based strategies for the treatment of GLM.

Would hyperbaric oxygen therapy be a supportive treatment method for refractory idiopathic granulomatous mastitis?

BACKGROUND

Refractory IGM causes patients to use antibiotics, steroid therapy, immunosuppressive agents for a very long time and even leads to surgical procedures resulting in the loss of breast tissue. Hyperbaric Oxygen Therapy (HBOT) is a frequently used method in the treatment of wounds that are difficult to heal. We thought that HBOT would be an alternative treatment method for refractory IGM patients.

METHODS

It is a retrospective cohort study on refractory IGM patients conducted at three tertiary care treatment centers between January 2021 and July 2023. The patients were evaluated in two groups: those who only took steroid treatment and those who received HBOT and steroid treatment. The demographic and clinical characteristics of the patients, the types of treatment applied and their responses to treatment were evaluated.

RESULTS

There were no significant differences generally in the demographic and clinical features in both groups. The incidence of multicentric GM was found to be higher in the HBOT group (66.67 %; p = 0.044). Although the recovery results were similar in both groups, the average daily steroid dose and duration of drug use were found to be higher in the group receiving only steroid treatment (16 mg vs. 4 mg and 270 days vs. 30 days) (p < 0.001).

CONCLUSION

In our study, we showed for the first time in the literature that HBOT is effective in the treatment of refractory IGM patients. Our study needs to be supported by prospective studies evaluating cost effectiveness and possible long term complications.

Diagnosis, Approach, and Clinical Classification of Idiopathic Granulomatous Mastitis: Consensus Report

Objective

The aim of the idiopathic granulomatous mastitis (IGM) consensus study was to evaluate the etiology, diagnostic steps, and differential diagnosis and propose a widely accepted clinical classification of this mysterious breast disease.

Method

The organization of a national IGM consensus was decided by the joint evaluation of the Turkish Federation of Breast Diseases Societies, SENATURK, and the Society of Breast Surgery. First, a working group of 11 members was formed, and a survey and workshop were organized to reach a common consensus. The modified Delphi method was used in the consensus methodology. Voting rates of 80% and above were considered as acceptance.

Results

The consensus was 45/50 (92%) that core needle biopsies are necessary for the diagnosis of IGM and 39/40 (97%) that a new clinical classification is needed. The proposed Turkish clinical classification of IGM was accepted by 94% in three rounds of voting.

Conclusion

This disease should be considered etiologically idiopathic. Tissue diagnosis and pathological evaluation are recommended for treatment. The proposed IGM Turkey classification was strongly accepted.

Novel insights: crosstalk with non-puerperal mastitis and immunity

The two primary types of non-puerperal mastitis (NPM) are granulomatous lobular mastitis (GLM) and plasma cell mastitis (PCM). Existing research indicates that immune inflammatory response is considered to be the core of the pathogenesis of GLM and PCM, and both innate and adaptive immune responses play an important role in the pathophysiology of PCM and GLM. However, the regulatory balance between various immune cells in these diseases is still unclear. Consequently, we present a comprehensive summary of the immune-related variables and recent advances in GLM and PCM.

Evaluation of significantly changed chemokine factors of idiopathic granulomatous mastitis in non-puerperal patients

Idiopathic granulomatous mastitis (IGM), a recurrent inflammation disease of the non-lactating breast, has had an increasing clinical morbidity rate in recent years, and its complicated symptoms and unclear etiology make it challenging to treat. This rare benign inflammatory breast disease, centered on the lobules, represents the most challenging type of non-puerperal mastitis (NPM), also known as non-lactating mastitis. In this study, patients diagnosed with IGM (M, n = 23) were recruited as cases, and patients with benign control breast disease (C, n = 17) were enrolled as controls. Cytokine microarray detection measured and analyzed the differentially expressed cytokine factors between IGM and control patients. Then, we verified the mRNA and protein expression levels of the significantly changed cytokine factors using Q-RT-PCR, ELISA, western blot, and IHC experiments. The cytokine factor expression levels significantly changed compared to the control group. We observed a significant increase between IGM and control patients in cytokine factors expression, such as interleukin-1β (IL-1β), monokine induced by gamma interferon (MIG), macrophage inflammatory protein (MIP)-1α, MIP-1β, tumor necrosis factor receptor 2 (TNF RII). Then, we verified the expression of these top five dysregulated factors in both mRNA and protein levels. Our results demonstrated the cytokine map in IGM and indicated that several cytokines, especially chemokines, were associated with and significantly dysregulated in IGM tissues compared to the control group. The chemokine factors involved might be essential in developing and treating IGM. These findings would be helpful for a better understanding of IGM and offer valuable insights for devising novel diagnostic and therapeutic strategies.

Immune pathogenesis of idiopathic granulomatous mastitis: from etiology toward therapeutic approaches

Idiopathic granulomatous mastitis (IGM) is a noncancerous, chronic inflammatory disorder of breast with unknown causes, posing significant challenges to the quality of life due to its high refractoriness and local aggressiveness. The typical symptoms of this disease involve skin redness, a firm and tender breast mass and mastalgia; others may include swelling, fistula, abscess (often without fever), nipple retraction, and peau d'orange appearance. IGM often mimics breast abscesses or malignancies, particularly inflammatory breast cancer, and is characterized by absent standardized treatment options, inconsistent patient response and unknown mechanism. Definite diagnosis of this disease relies on core needle biopsy and histopathological examination. The prevailing etiological theory suggests that IGM is an autoimmune disease, as some patients respond well to steroid treatment. Additionally, the presence of concurrent erythema nodosum or other autoimmune conditions supports the autoimmune nature of the disease. Based on current knowledge, this review aims to elucidate the autoimmune-favored features of IGM and explore its potential etiologies. Furthermore, we discuss the immune-mediated pathogenesis of IGM using existing research and propose immunotherapeutic strategies for managing this condition.

Construction of a Multi-Indicator Model for Abscess Prediction in Granulomatous Lobular Mastitis Using Inflammatory Indicators

Background

Granulomatous lobular mastitis (GLM) is a chronic inflammatory breast disease, and abscess formation is a common complication of GLM. The process of abscess formation is accompanied by changes in multiple inflammatory markers. The present study aimed to construct a diagnosis model for the early of GLM abscess formation based on multiple inflammatory parameters.

Methods

Based on the presence or absence of abscess formation on breast magnetic resonance imaging (MRI), 126 patients with GLM were categorised into an abscess group (85 patients) and a non-abscess group (41 patients). Demographic characteristics and the related laboratory results for the 9 inflammatory markers were collected. Logistics univariate analysis and collinearity test were used for selecting independent variables. A regression model to predict abscess formation was constructed using Logistics multivariate analysis.

Results

The univariate and multivariate analysis showed that the N, ESR, IL-4, IL-10 and INF-α were independent diagnostic factors of abscess formation in GLM (P<0. 05). The nomogram was drawn on the basis of the logistics regression model. The area under the curve (AUC) of the model was 0.890, which was significantly better than that of a single indicator and the sensitivity and specificity of the model were high (81.2% and 85.40%, respectively). These results predicted by the model were highly consistent with the actual diagnostic results. The results of this calibration curve indicated that the model had a good value and stability in predicting abscess formation in GLM. The decision curve analysis (DCA) demonstrated a satisfactory positive net benefit of the model.

Conclusion

A predictive model for abscess formation in GLM based on inflammatory markers was constructed in our study, which may provide a new strategy for early diagnosis and treatment of the abscess stage of GLM.

Spontaneous, idiopathic granulomatous mastitis in a pregnant patient: A case report and review of the literature

Idiopathic granulomatous mastitis is a rare breast condition of unclear etiology. Its course is often rapidly progressive, slow to resolve, and can have a high rate of recurrence. Clinical presentation can mimic breast abscess, infectious mastitis, and carcinoma of the breast, generating a diagnostic challenge. Histopathological analysis is required to make the diagnosis after common conditions are excluded. There is no standard treatment, however surgical excision, steroid treatment, and observation are commonly reported approaches. Here, we describe a complex case of a multiparous patient presenting with idiopathic granulomatous mastitis at 32 weeks gestation. In this review, we highlight the importance of collaboration amongst a multidisciplinary team for effective diagnosis and treatment. We discuss the use of oral corticosteroids in the antenatal period and illustrate the patient support required to both facilitate successful breastfeeding in the postpartum period and promote recovery.

The Distinct Pattern of Granulomatous Lobular Mastitis with Erythema Nodosum: More Severe Conditions and Extensive Lesions

PURPOSE

Granulomatous lobular mastitis (GLM) is a benign inflammatory disease of the mammary gland with unknown etiology. Erythema nodosum (EN) is a rare, extramammary symptom of GLM. The purpose of this article was to investigate the clinical features of EN associated with GLM.

METHODS

We recruited 102 GLM patients diagnosed between December 2018 and December 2021 at Renmin Hospital of Wuhan University. The clinical characteristics and laboratory indices of the EN group (n = 12) and the non-EN group (n = 90) were compared.

RESULTS

The proportion of GLM patients with lesions involving ≥2 quadrants and high peripheral white blood cell count, absolute neutrophil count and neutrophil-to-lymphocyte ratio (NLR) was larger in the EN group than in the non-EN group (p = 0.002, 0.025, 0.014, 0.002, respectively). The duration of EN was longer in GLM patients with EN than in GLM patients without EN (p = 0.005). GLM patients with EN had more abscesses and sinus tracts than those without EN (p = 0.003, 0.038). Lesions involving ≥2 quadrants and the NLR were positively associated with the occurrence of EN (R = 0.304, 0.0302, p = 0.002, 0.002). Receiver operating characteristic curve analysis revealed that the area under the curve of the NLR was 0.770. When NLR > 5.73, the sensitivity and specificity of predicting EN were 66.67% and 87.78%, respectively.

CONCLUSION

Our findings suggest that GLM concomitant with EN suggests the presence of a more severe condition and extensive lesions.

Predisposing Factors for Granulomatous Lobular Mastitis: A Case-Control Study

Background

Despite the rising incidence rate of granulomatous lobular mastitis (GLM), uncertainties persist about its etiologic and predisposing factors to guide clinical treatment and early prevention. The objective of this study is to explore the predisposing factors for GLM.

Patients and methods

This case-control study was conducted from 2018 to 2021 at Beijing Hospital of Traditional Chinese Medicine, Capital Medical University. Patients with GLM (cases) were matched with healthy examinees (controls) in a 1:1 ratio according to gender and living area. We analyzed their demographic features and investigated 75 factors that may be relevant to GLM using a standard questionnaire. Univariate and multivariable binary conditional logistic regression analyses were used to compare the differences between the two groups and evaluate the predisposing factors that may induce GLM.

Results

There were 594 female GLM patients and 594 matched controls included in the study. The average age of the cases was 32.78 years (mainly 20 to 40). The incidence was high within five years after childbirth, and lesions were mainly in the unilateral breast. Univariate and multivariable conditional logistic regression analyses obtained six relevant factors and six high-risk factors. The six relevant factors included age, marriage, emotional abnormality, high prolactin, psychiatric drug intake, and sex hormone intake. Additionally, the independent high-risk factors for GLM included gestation, nipple invagination, blunt trauma, non-iatrogenic massage, lactation disorder, and nipple discharge (odds ratio (OR)=17.378, 8.518, 4.887, 3.116, 2.522, 1.685, P<0.05). Menopause was an independent protective factor (OR=0.249, P<0.05).

Conclusion

The factors that increase milk and secretion production in the mammary duct are the main risk factors of GLM, especially when the nipples are invaginated. These factors can obstruct the duct and induce inflammation. Additionally, hormonal disorders, extrinsic trauma, and emotional abnormalities can accelerate the occurrence of GLM.

Clinical, microbiological, immunological and hormonal profiles of patients with granulomatous mastitis

Various studies on the etiology and other aspects of granulomatous mastitis (GM) have been performed; however, a lot of controversies have arisen. The present study aimed to present the clinicopathological findings and identify the sensitivity and resistance of isolated bacteria in patients with GM. In this cross-sectional study 63 female patients with a confirmed histopathological diagnosis of GM were included. A core needle biopsy was conducted for the patients to obtain a sample for histopathological examination and bacterial culture. In total, 46 types of antibiotics were used to determine the sensitivity and resistance of each isolated bacterial species. All the medical and clinical records of the patients were acquired through the completion of a questionnaire form in person or, if necessary, through the evaluation of their medical records in the database of the relevant center. The majority of the patients were in the premenopausal or perimenopausal period. GM was unilateral in 58.7% of the patients. The most common symptom was pain, followed by fever and chills. The mean ranges of the erythrocyte sedimentation rate, C-reactive protein, IL-6, IL-17, C5a, white blood count, neutrophil-to-lymphocyte ratio, and prolactin tests were significantly elevated in comparison to the normal ranges. In total, nine different bacterial species were isolated from the bacterial culture of the core biopsy samples, and 50% of the isolated bacterial species were sensitive to trimethoprim-sulfamethoxazole. Since there is no consensus on the etiology of GM, any additional studies related to this aspect expand the current understanding of this puzzling condition.

Is peripheral blood immunophenotyping useful to understand the etiology of Idiopathic Granulomatous?

BACKGROUND

The etiology of idiopathic granulomatous mastitis (IGM) has not been clearly established. However, autoimmunity has recently become popular in etiopathogenesis. We aimed to investigate the immunophenotyping of immune cells to help clarify the etiopathogenesis of the disease.

METHODS

Patients with IGM and healthy volunteers were included in the study. Patients were divided into active and remission groups based on their disease status. The ratios of total T cells, helper T cells, cytotoxic T cells, natural killer cells, regulatory T cells, and monocyte subtypes were measured using flow cytometry. In addition, age, complete blood count for leukocyte, lymphocyte, neutrophil, and eosinophil counts, and the smoking status of all volunteers were evaluated.

RESULTS

A total of 33 volunteers, including 11 patients with active IGM, 10 patients with remission IGM, and 12 healthy volunteers, were included in the study. The neutrophil, eosinophil, neutrophil/lymphocyte, and non-classical monocyte values were significantly higher in IGM patients than in healthy volunteers. Additionally, the CD4⁺ CD25⁺ CD127^- regulatory T cell was significantly lower in IGM patients than in healthy volunteers. Furthermore, neutrophil, neutrophil/lymphocyte ratio, CD4⁺ CD25⁺ CD127^- regulatory T cells, and non-classical monocytes showed significant differences when IGM patients were divided into active and remission groups. IGM patients had higher smoking rates, but this was not statistically significant.

CONCLUSION

The changes in many cell types evaluated in our study were similar to the cell profiles of some autoimmune diseases. This could provide minor evidence to suggest that IGM is an autoimmune granulomatous disease with a local course.

Autoimmune rheumatic diseases associated with granulomatous mastitis

Granulomatous mastitis (GM) is a benign, inflammatory condition of the breast that mainly affects women of reproductive age. Although its pathogenesis remains unknown, previous studies revealed an association between autoimmune rheumatic diseases (ARDs) and GM in a subset of patients implicating immune-mediated mechanisms. The aim of this narrative review was to identify and describe the ARDs associated with GM to shed further light on disease pathogenesis. We conducted a comprehensive literature search of patients presenting with GM and coexisting ARDs using electronic databases. An association between GM and various ARDs has been reported, including sarcoidosis, systematic lupus erythematosus, granulomatosis with polyangiitis, psoriasis/psoriatic arthritis, familial Mediterranean fever, ankylosing spondylitis, Sjogren's syndrome, rheumatoid arthritis, and erythema nodosum, with the most common being granulomatous mastitis-erythema nodosum-arthritis syndrome (GMENA), granulomatosis with polyangiitis (Wegener's) and sarcoidosis. In addition, clinical characteristics, diagnostic and therapeutic approaches were recorded. Further research is warranted to better understand the association between GM and ARDs and raise awareness amongst rheumatologists.

Ozone therapy restores immune dysfunction in refractory idiopathic granulomatous mastitis as a novel potential therapeutic approach

Immunological dysfunction has been suggested to play a major role in the pathogenesis of idiopathic granulomatous mastitis (IGM). We recently showed that ozone therapy was effective in patients with steroid-resistant IGM. This study assessed alterations in intracellular cytokine expression patterns in different T-lymphocyte subsets after ozone therapy in refractory IGM. Peripheral blood T lymphocyte subsets (CD8⁺ , CD4⁺ , CD4⁺ CD25⁺ CD127^- ) were analyzed via flow-cytometry for intracellular cytokine expressions IFN-γ, TNF-α, IL-10, and TGF-β before and after completion of 4-month systemic ozone therapy. Ozone therapy significantly increased the CD4⁺ IFN-γ⁺ (p = 0.032), CD4⁺ TNF-α⁺ (p = 0.028), and the CD8⁺ TNF-α⁺ (p = 0.012) T cells. In contrast, significant decreases in CD4⁺ IL-10⁺ (p = 0.047) and CD8⁺ IL-10⁺ T cells (p = 0.022) and CD4⁺ CD25⁺ CD127^-//low Treg cells secreting TGF-β (p = 0.005) were found after ozone therapy. When patients were analyzed according to the response to ozone therapy, patients with a complete remission were more likely to have increased CD3^- CD16⁺ CD56⁺ natural killer cells (p = 0.0027) and decreased CD19⁺ B lymphocytes (p = 0.046) following ozone therapy. Our results suggest that ozone therapy stimulated a T-helper-1 response associated with IFN-γ production and downregulation of TGF-β expression in CD4⁺ CD25⁺ CD127^- Treg cells. These alterations in the immune system following ozone therapy can improve wound healing and restore immune dysfunction in patients with refractory IGM.

Clinical characteristics and microbiota analysis of 44 patients with granulomatous mastitis

Introduction

Granulomatous mastitis (GM) is a chronic inflammatory breast disease. In recent years, the role of Corynebacterium in GM onset has received more and more attention. This study aims to detect the dominant bacterium in GM patients and analyze the association between clinical characteristics and infectious factors.

Methods

In this study, 88 samples from 44 GM patients, six acute lactation mastitis (ALM) patients, and 25 non-inflammatory breast disease (NIB) patients were divided into a GM pus group, a GM tissue group, an ALM pus group, and a NIB tissue group; then, 16S ribosomal DNA sequencing was used to explore their microbiota. The clinical data of all 44 GM patients were also retrospectively collected and analyzed to determine their relationship with infection.

Results

The median age of the 44 GM patients was 33 years, and 88.6% of patients had primary-onset cases, while 11.4% were recurrences; additionally, 89.5% of patients were postpartum and 10.5% were nulliparous. The serum prolactin level was abnormal in nine patients (24.3%). Samples from 15 GM patients (34.1%) had a Corynebacterium abundance of >1% (1.08-80.08%), with eight (53.3%) displaying an abundance of >10%. Corynebacterium was the only genus with significant differences between the GM pus group and the other three groups (p < 0.05). Corynebacterium kroppenstedtii was the predominant Corynebacterium species. Among clinical characteristics, a statistical difference in breast abscess formation was observed according to Corynebacterium abundance in Corynebacterium-positive and- negative patients (p < 0.05).

Discussion

This study explored the relationship between Corynebacterium infection and GM, compared the clinical characteristics between Corynebacterium-positive and- negative patients, and provided support for the role of Corynebacterium species-in particular, C. kroppenstedtii-in the pathogenesis of GM. The detection of Corynebacterium can predict GM onset, especially in patients with high prolactin levels or a history of recent lactation.

Current Research Describing the Role of CD4+ T Lymphocyte Subsets in the Pathogenesis of Granulomatous Lobular Mastitis

Background: Granulomatous lobular mastitis (GLM) is a rare, benign, chronic inflammatory illness of the mammary gland with an unknown cause. Many scholars believe that the pathogenesis of GLM is mediated by autoimmunity. This article reviews the progress of the role of CD4+ T lymphocyte subsets in the development of GLM to explore potential therapeutic targets.Methods: Original articles from inception to October 2021 were systematically searched by two members on PubMed and China National Knowledge Infrastructure.Results: Current studies have confirmed the presence of disorders of several immune molecules in the serum and tissue microenvironment of GLM patients, including interleukin (IL) -2, IL-4, IL-6, and IL-10. This may be related to the dysregulation of Th1/Th2 and Th17/Treg balance.Conclusions: Altered expression and the malfunctioning of Th, Treg, and associated cytokines may contribute to GLM pathogenesis. Immune molecules and immune-related pathways may be potential targets and breakthroughs for future GLM treatment.

Differential expression profiles of miRNA in granulomatous lobular mastitis and identification of possible biomarkers

The etiology and pathogenesis of granulomatous lobular mastitis (GLM) remain largely elusive and the expression levels and regulatory roles of microRNAs (miRNAs or miRs) in GLM have remained mostly undetermined. In the present study, the miRNAs that were differentially expressed in breast biopsy samples from patients with GLM and normal tissue adjacent to fibroadenoma were analyzed, a comprehensive differential expression profile of miRNAs was provided and potential biomarkers were screened out. The expression profile of miRNAs was determined by high-throughput sequencing in the tissues of patients with GLM and healthy controls. Significantly differentially expressed miRNAs were screened by threshold setting and cluster analysis and their target genes were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. Finally, circulating differentially expressed miRNAs between the GLM and control groups were further analyzed by reverse transcription-quantitative PCR (RT-qPCR). A total of 31,077 miRNAs were detected by high-throughput sequencing. By using the cutoff criteria of |log2 fold change|>2.5 and q<0.001, 13 miRNAs that were indicated to be GLM biomarkers were screened out. The expression levels of these 13 miRNAs in the GLM group were higher than those in the control group. GO and KEGG enrichment analyses suggested that the occurrence and development of GLM may be associated with autoimmune inflammation, metabolism and pathogenic organisms. miR-451a and miR-5571-3p were confirmed to be significantly increased in the serum of patients with GLM compared with their levels in the serum of healthy volunteers, which suggests that they may be used as biomarkers of GLM. To the best of our knowledge, the present study was the first report detailing genome-wide miRNA profiling of patients with GLM compared with controls. The possible targets and pathways of GLM were evaluated by bioinformatics analysis. The present study identified 13 differentially expressed miRNAs with important theoretical significance and potential application. Furthermore, miR-451a and miR-5571-3p were verified by RT-qPCR as possible biomarkers of GLM.

Local Steroid Treatment: An Effective Procedure for Idiopathic Granulomatous Mastitis, Including Complicated Cases

PURPOSE

To evaluate the effectiveness of treatment with topical and intralesional steroids for idiopathic granulomatous mastitis (IGM) and to compare with surgical methods.

METHODS

Data were retrospectively collected from records. Intralesional steroid injection and topical steroid administration, hereafter referred to as local steroid treatment (LST) were applied in Group 1. Surgery (local excision, wide excision, and mastectomy) was performed in Group 2. In Group 1, changes in lesion sizes were recorded and factors complicating treatment were identified. The Numeric Pain Rating Scale was used to determine subjective pain. LST and surgery were compared with regard to: pain before and after the treatment; complication rate; recurrence rate; and treatment cost.

RESULTS

There were 38 and 48 patients in Group 1 and Group 2, respectively. In the LST group, 72 lesions were present and 70 of 72 (97%) responded completely to treatment. Pretreatment median maximum diameter was 23.50 (15.25-35.25) mm, which regressed to 16 (12-25) mm after the first session. While the pretreatment pain scores of Group 1 and Group 2 were similar (p = 0.756), there was a significant difference in the post-treatment pain scores (p < 0.001). No recurrence occurred in any patients in Group 1, while recurrence developed in 15 (31.2%) patients in Group 2 (p < 0.001).

CONCLUSION

LST is a treatment for IGM that is cheap, with high efficiency, negligible recurrence, and has good esthetic outcome. Our results suggest that LST should be the first-line treatment option for all IGM patients, including complicated cases.

New Insights of Corynebacterium kroppenstedtii in Granulomatous Lobular Mastitis based on Nanopore Sequencing

BACKGROUND

The etiology of granulomatous lobular mastitis (GLM) remains unknown. This study aimed to detect bacteria in GLM using Nanopore sequencing and identify the relationship between GLM and Corynebacterium kroppenstedtii.

METHODS AND MATERIALS

The bacterial detection on fresh samples (including breast pus and tissue) of 50 GLM patients using nanopore sequencing and culture methods. The bacterial detection rate of participants with different stages were compared and analyzed. Formalin-fixed and paraffin-embedded (FFPE) tissues from 39 patients were performed on Gram staining to identify Gram-positive bacilli (GPB) within lipid vacuoles. Moreover, the clinicopathological characteristics of GLM patients in different bacterial subgroups were also conducted.

RESULTS

In 50 GLM patients, the detection rate of bacteria was 78% using nanopore sequencing method, especially in the early stage of GLM (over 80%), which was significantly higher than that using culture methods (24%, p < 0.001). The dominant bacteria were Corynebacterium species (64%), especially for the Corynebacterium kroppenstedtii. The detection rate of C. kroppenstedtii in nanopore sequencing method (56%) was higher than that in culture methods (16%, p < 0.001). Gram staining positive of bacteria in 7 patients, and 5 of them were C. kroppenstedtii. Thirty-one patients (31/39, 79.5%) exhibited typical histological structure of cystic neutrophilic granulomatous mastitis (CNGM), and eighteen patients detected with C. kroppenstedtii.

CONCLUSION

Nanopore sequencing showed rapid and accurate bacteria detection over culture method in GLM patients. GLM is not sterile inflammation and closely related to C. kroppenstedtii. CNGM was associated with Corynebacterium infection, especially for C. kroppenstedtii.

Serum C-Reactive Protein and Interleukin-6 Levels as Biomarkers for Disease Severity and Clinical Outcomes in Patients with Idiopathic Granulomatous Mastitis

Idiopathic granulomatous mastitis (IGM) is a rare inflammatory breast disease mimicking breast cancer. Limited research has been conducted on the application of serum biomarkers. This study aims to investigate the association of serum biomarkers with disease severity in patients with IGM. From November 2011 to March 2020, medical records of patients with IGM were reviewed. Serum cytokine levels were measured in patients and healthy controls between July 2018 and March 2020. A total of 41 patients with histologically proven IGM were found. Serum interleukin (IL)-6 level was significantly higher in patients with IGM (n = 11) than healthy controls (n = 7). Serum IL-6 and C-reactive protein (CRP) levels were significantly higher in patients with severe disease than mild and moderate disease. Serum IL-6 (Spearman’s ρ = 0.855; p < 0.001) and CRP (Spearman’s ρ = 0.838; p = 0.001) levels were associated with time to resolution. A higher serum CRP level was associated with a longer time to resolution (B = 0.322; p < 0.001) in multiple linear regression analysis. Serum IL-6 and CRP levels can be used as biomarkers for the evaluation of disease severity in IGM. IL-6 may play a crucial role in the immunopathology of IGM.

Idiopathic Granulomatous Mastitis: Etiology, Clinical Manifestation, Diagnosis and Treatment

Idiopathic granulomatous mastitis (IGM) is a rare form of chronic inflammatory breast disease. Although it is a benign breast lesion, it may be sometimes difficult to distinguish from breast cancer. The cause of IGM is unknown, but may be associated with autoimmunity, abnormal hormone levels and infection. While the clinical manifestations of IGM involve various manifestations of inflammation, the diagnosis is principally established by histopathology, characterized by non-caseating granulomas and microabscess formation centered on the breast lobules. Therapeutic options for IGM range from observation to various medical treatments, such as steroids, immunosuppressants, and antibiotics, to surgical intervention, particularly if secondarily infected. Given that the controversy on etiology and treatment choices, we accomplished the present review through reviewing IGM-related literature published in 'Pubmed' and 'Web of science' databases during 1997 to 2020, aiming to provide the basis for rational clinical diagnosis and treatment.

Granulomatous mastitis, erythema nodosum and arthritis syndrome: case-based review

Granulomatous mastitis (GM) is a rare form of inflammatory breast condition associated with unilateral or bilateral breast pain, swelling and mass formation. Although the disease pathogenesis remains unknown, several reports have associated GM with manifestations such as erythema nodosum and occasionally with arthritis, suggesting that GM might have an autoimmune disease component. We aim to describe two cases of coexistence of GM, erythema nodosum, and arthritis. We also conducted a literature review to comprehensively assess and describe the characteristics of patients with GM, erythema nodosum, and arthritis, and identify effective treatment options. A literature review was conducted using PubMed and EMBASE, and 14 case reports/series were retrieved, with a total number of 29 patients. All patients are women and unilateral breast involvement was evident in the majority of patients. Nine patients (31%) presented with arthritis, 6 patients (20.7%) had a fever, and 6 patients (20.7%) developed the symptoms during pregnancy. All patients had normal chest radiograph and tissue cultures were negative. In most of the cases (n = 25, 86.2%), symptom improvement was observed with glucocorticoids and four patients (13.8%) underwent surgical treatment for the GM. Given the clinical characteristics of patients with GM, with erythema nodosum, with or without arthritis, and the positive response to glucocorticoids, we propose that the described phenotype represents an underrecognized systemic autoimmune disease that could be designated by the acronym "GMENA" (granulomatous mastitis, erythema nodosum, arthritis) syndrome. Further studies are needed to elucidate the pathogenesis of the syndrome.

The Effect of Soluble TREM-1 in Idiopathic Granulomatous Mastitis

Background and objectives: The aim of this study is to investigate the effect of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in idiopathic granulomatous mastitis (IGM).Methods: This case-control study was conducted in Saglik Bilimleri and Necmettin Erbakan Universities. Sixty patients with IGM diagnosis (Group P) and 25 healthy females as control group (Group C) were included. Group P was divided into two subgroups according to the activity of disease: patients with active lesion (Group P_A), and patients without any symptoms, in remission (Group P_R). The ELISA method was used to measure sTREM-1 level.Results: Group P's sTREM-1 were higher than Group C (p < .0001). The difference between sTREM-1 levels of Groups P_A, P_R and C was significant statistically (p < .0001). Group P_A's sTREM-1 levels were higher than Group C (p < .0001). Also, sTREM-1 levels of Group P_R were higher than Group C (p = .006). When sTREM-1 levels of patients receiving steroid therapy and did not in Group P_R were analyzed, the sTREM-1 levels of the patients not receiving steroid treatment were found to be statistically higher than Group C (p = .002). Although the sTREM-1 levels of the patients who did not receive steroid therapy were higher than those who received steroid therapy, the difference was not statistically significant (p > .05).Conclusion: We concluded that the detected high sTREM-1 levels contributed to inflammation in IGM. In particular, blockade of TREM may be a promising treatment option in resistant or multiple recurrent patients.

What are the new findings with regard to the mysterious disease idiopathic granulomatous mastitis?

PURPOSE

To review the demographic and clinical features and the success rates of treatment approaches for idiopathic granulomatous mastitis (IGM).

METHODS

A total of 134 patients diagnosed with IGM pathologically and treated by a single breast surgeon were retrospectively analyzed.

RESULTS

The time between the occurrence of symptoms and the last delivery was < 24 months in 25 (23.1%), 24-48 months in 51 (38.1%), and > 48 months in 52 (38.8%). The difference was statistically significant (p = 0.002). Although there was no significant difference, seasonal fluctuations were noticed, with the incidence being slightly higher during late spring and summer. Bilateral disease was present in 10 (7.5%) patients. Seven patients (5.2%) had erythema nodosum. The treatment approaches were conservative in 42, surgical procedures in 48, steroid treatment in 18, and surgical procedure + steroid treatment in 24. The median recovery time with conservative approaches was lower than that with surgical procedure + steroid treatment (p < 0.0001). Recurrence developed in 10 patients (7.7%).

CONCLUSION

Clinical differences were detected among the patients with IGM, and classification of patients by severity is needed to plan the optimal treatment approach. Seasonal fluctuations suggest the possibility of an immunological disease rather than a surgical disease.

The Clinical Utility of Autoantibodies in Patients with Idiopathic Granulomatous Mastitis

BACKGROUND

Although the etiopathogenesis of idiopathic granulomatous mastitis (IGM) is still controversial, recently autoimmunity and immune dysregulation have been emphasized. The aim of this study is to investigate the clinical utility of autoantibodies in IGM.

MATERIAL AND METHODS

Rheumatoid factor (RF), antinuclear antibody (ANA), anti-double stranded DNA antibody (anti-ds-DNA), anti-cyclic citrullinated peptides antibody (anti-CCP) and perinuclear anti-neutrophil cytoplasmic antibody (pANCA) levels were investigated in pathologically diagnosed IGM patients (Group IGM) and healthy women (Group C). IGM patients were divided into two groups as those with active symptoms and signs (Group IGM_A) and those without clinical and radiological findings (Group IGM_R).

RESULTS

While, in Group IGM, the positivity of RF, ANA, anti-ds-DNA, pANCA and anti-CCP was 13.1%, 3.3%, 1.6%, 0%, and 3.3%, respectively, in Group C, they were 13.3%, 0%, 0%, 0%, and 0%, respectively. The differences were not statistically significant (p > .05). In Groups IGM_A, IGM_R and C, RF positivity was 10%, 16.1%, and 13.3%, respectively. The ANA positivity of Groups IGM_A, IGM_R and C was 0%, 6.5%, and 0%, respectively. Groups IGM_A, IGM_R and C's anti-ds-DNA positivity were 0%, 3.2%, and 0%, respectively. In all groups, pANCA was negative. The anti-CCP positivity of Groups IGM_A, IGM_R and C was 6.7%, 0%, and 0%, respectively.

CONCLUSION

Our findings did not support the clinical utility of autoantibodies including RF, ANA, anti-ds-DNA, pANCA and anti-CCP in IGM.

Bacteria Associated with Granulomatous Lobular Mastitis and the Potential for Personalized Therapy

Granulomatous lobular mastitis (GLM), also known as idiopathic granulomatous mastitis (IGM), is a chronic inflammatory lesion of the breast. The incidence of GLM has been increasing in recent years, especially among young women. The etiologies of GLM have not been fully elucidated but are associated with autoimmunity and bacterial infection. Bacteria, especially Corynebacterium species, play important roles in GLM. In this article, we review research progress regarding the bacteriology of GLM attained with the application of several new high-throughput detection techniques. Accurate detection might be important for deepening our understanding of the pathogenesis of GLM and hold promise for personalized GLM therapy.

The Role of Regulatory T and B Cells in the Etiopathogenesis of Idiopathic Granulomatous Mastitis

BACKGROUND AND OBJECTIVES

The aim of this study was to evaluate the role of T- and B-regulatory cells (Tregs and Bregs) in the pathogenesis of idiopathic granulomatous mastitis (IGM).

METHODS

This study includes 47 patients with pathologically proven IGM (Group P) and 26 healthy subjects (Group C). The patients in Group P were divided into two groups according to whether their lesions were active (Group P_A, n: 21) or in remission (Group P_R, n: 26). By using flow-cytometry, the frequencies of CD3⁺CD4⁺CD45RA^-Foxp3^high activated Tregs (aTregs), CD3⁺CD4⁺CD45RA^-Foxp3^low non-suppressive Tregs, CD3⁺CD4⁺CD45RA⁺Foxp3^low resting Tregs (rTregs), CD3⁺CD4⁺CD25⁺Foxp3^- T-effector cells (Teff), total Tregs and Bregs were analyzed in all subjects.

RESULTS

The frequency of the Teff cells was statistically higher in Group P when compared with Group C (p =.004). The Foxp3 expression of Treg cells and the frequency of non- suppressive Tregs in Group P were statistically lower than Group C (p =.032 and p =.02, respectively). In addition, Group P_R's Foxp3 expressions were statistically lower than Group C (p =.027); Group P_R's aTregs ratio was statistically lower than Group P_A (p =.021); and the non-suppressive Tregs ratio of Group P_R was lower than both Group P_A and Group C (p =.006 and p <.0001). No significant differences were seen Bregs and B cell subsets.

CONCLUSION

Significant changes in Foxp3 expression and Treg subsets were seen in patients with active IGM lesion and in remission. This study shows an intrinsic defect of Tregs in patients with IGM.