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

Is granulomatous mastitis a rheumatologic disease? The emerging role of rheumatologists in disease management

Granulomatous mastitis (GM) is a rare, chronic inflammatory breast disease characterized by non-caseating granulomas. While its etiology remains unclear, emerging evidence supports an immune-mediated pathogenesis with parallels to autoimmune rheumatic diseases. This review explores the inflammatory mechanisms underlying GM, emphasizing the roles of cytokines such as TNF-α, IL-6, and the Th17 axis in sustaining granulomatous inflammation. Traditional management has centered on surgical excision, but high recurrence rates have prompted a shift toward immunosuppressive therapy, particularly corticosteroids and disease-modifying antirheumatic drugs (DMARDs). Recent studies suggest that DMARDs offer effective disease control while minimizing the adverse effects of long-term steroid use. Given the autoimmune overlap and the efficacy of targeted immunomodulatory therapy, rheumatologists play an increasingly critical role in GM management. This review advocates for increased awareness of GM within the rheumatology community and underscores the need for further research to refine therapeutic strategies.

Granulomatous mastitis - Case report

INTRODUCTION AND IMPORTANCE

Idiopathic granulomatous mastitis (IGM) is a rare, benign, and chronic inflammatory breast disease with unclear etiology and no standardized treatment. It often presents as a painful breast mass that mimics breast cancer, necessitating thorough diagnostic evaluation.

CASE PRESENTATION

This report discusses a case of a 39-year-old pregnant woman with IGM associated with erythema nodosum, a poorly understood co-occurrence. Initial treatment included antibiotics and surgical drainage for an abscess. Despite multiple interventions, including corticosteroids and methotrexate, the disease persisted with recurrent episodes.

CLINICAL DISCUSSION

This case underscores the complexities of managing IGM, highlighting its association with systemic manifestations such as erythema nodosum. Current therapeutic approaches range from conservative management to immunosuppressive therapy and surgery, with outcomes varying widely.

CONCLUSION

Further studies are needed to elucidate the pathophysiology and establish optimal treatment strategies for IGM, particularly in the context of systemic involvement.

Correlation Analysis and Construction of a Predictive Model Between Contrast-Enhanced Ultrasound Features and the Risk of Recurrence in Granulomatous Mastitis

BACKGROUND

Granulomatous mastitis (GM) is an inflammatory breast condition with high recurrence risk, often complicating management. Existing imaging techniques provide limited predictive insight. This study aims to analyze the correlation between contrast-enhanced ultrasound (CEUS) features and the risk of GM recurrence, developing a predictive model.

METHODS

A retrospective review included 510 patients diagnosed with GM from 2017 to 2022, divided into non-recurrence (non-recurrence, n=389) and recurrence (recurrence, n=121) groups. CEUS was conducted to assess lesion perfusion and enhancement patterns. Key features such as isoenhancement and perfusion defects were analyzed. Correlation analyses, ROC, univariate, and multivariate analyses informed the predictive model construction using XGBoost. External validation was performed to confirm model reliability.

RESULTS

CEUS features like homogeneous (rho=0.137, P=0.002) and heterogeneous isoenhancement (rho=0.134, P=0.002) showed significant correlations with recurrence risk. Perfusion defects (rho=0.127, P=0.004) and not smooth edge lines of defects (rho=0.234, P<0.001) were also associated. The predictive model, integrating CEUS patterns, achieved an area under the curve (AUC) of 0.822, indicating strong predictive validity. External validation confirmed the model's efficacy (AUC=0.808).

CONCLUSION

CEUS imaging reveals specific vascular and enhancement patterns that correlate with the risk of GM recurrence, providing critical diagnostic and prognostic value.

A recurrence model for non-puerperal mastitis patients based on machine learning

OBJECTIVE

Non-puerperal mastitis (NPM) is an inflammatory breast disease affecting women during non-lactation periods, and it is prone to relapse after being cured. Accurate prediction of its recurrence is crucial for personalized adjuvant therapy, and pathological examination is the primary basis for the classification, diagnosis, and confirmation of non-puerperal mastitis. Currently, there is a lack of recurrence models for non-puerperal mastitis. The aim of this research is to create and validate a recurrence model using machine learning for patients with non-puerperal mastitis.

METHODS

We retrospectively collected laboratory data from 120 NPM patients, dividing them into a non-recurrence group (n = 59) and a recurrence group (n = 61). Through random allocation, these individuals were split into a training cohort and a testing cohort in a 90%:10% ratio for the purpose of building the model. Additionally, data from 25 NPM patients from another center were collected to serve as an external validation cohort for the model. Univariate analysis was used to examine differential indicators, and variable selection was conducted through LASSO regression. A combination of four machine learning algorithms (XGBoost、Logistic Regression、Random Forest、AdaBoost) was employed to predict NPM recurrence, and the model with the highest Area Under the Curve (AUC) in the test set was selected as the best model. The finally selected model was interpreted and evaluated using Receiver Operating Characteristic (ROC) curves, calibration curves, Decision curve analysis (DCA), and Shapley Additive Explanations (SHAP) plots.

RESULTS

The logistic regression model emerged as the optimal model for predicting recurrence of NPM with machine learning, primarily utilizing three variables: FIB, bacterial infection, and CD4+ T cell count. The model showed an AUC of 0.846 in the training cohort and 0.833 in the testing cohort. The calibration curve indicated excellent calibration of the model. DCA revealed that the model possessed favorable clinical utility. Furthermore, the model effectively achieved in the external validation group, with an AUC of 0.825.

CONCLUSION

The machine learning model developed in this study, serving as an effective tool for predicting NPM recurrence, aids doctors in making more individualized treatment decisions, thereby enhancing therapeutic efficacy and reducing the risk of recurrence.

>Efficacy of disease-modifying antirheumatic drugs in the treatment of granulomatous mastitis: a systematic review

INTRODUCTION

Idiopathic granulomatous mastitis (IGM) is an inflammatory breast disorder of unknown etiology. This benign condition can mimic the clinical presentation of breast cancer and is characterized by symptoms such as breast pain, erythema, and swelling. Over the past few years, Disease-Modifying Antirheumatic Drugs (DMARDs) have been increasingly used to manage this condition. However, strong evidence to support their use is lacking.

OBJECTIVES

This systematic review aimed to summarize the evidence and evaluate the efficacy of DMARDs in the management of IGM.

METHODS

A systematic literature review, adhering to PRISMA guidelines, was conducted across electronic databases, including PubMed, EMBASE, SCOPUS, directory of open access journals (DOAJ) and Cochrane Library from their inception until May 2024. We included retrospective and prospective studies while excluding case reports and case series of less than 10 patients.

RESULTS

Eighteen studies met our eligibility criteria. Fifteen studies were retrospective, while 2 were prospective. No randomized controlled trials were identified. Of these, 16 papers examined the effect of methotrexate on IGM, revealing significant disease improvement in most cases. Several of the studies indicated that patients treated with azathioprine and mycophenolate mofetil also achieved favorable responses.

CONCLUSION

Given the rarity of IGM, only a limited number of studies have explored the use of DMARDs as a pharmacological treatment option. A significant barrier to advancing our understanding is the substantial heterogeneity in the quality and volume of data provided by these studies. Therefore, there is a need for well-designed, randomized, placebo-controlled trials to rigorously assess the efficacy of DMARDs in the treatment of IGM.

Is Idiopathic Granulomatous Mastitis a Subgroup of Systemic Lupus Erythematosus? A Preliminary Study

Objective: The study aimed to use the systemic lupus erythematosus risk probability index (SLERPI) to assess if patients with idiopathic granulomatous mastitis (IGM) meet the criteria for systemic lupus erythematosus (SLE). Methods: A total of 62 patients with IGM and 55 age- and sex-matched healthy controls (HC) were enrolled. The study included patients who were over 18 years old and had been diagnosed with IGM using a true-cut biopsy. The participants' demographic, clinical, and laboratory data were recorded in detail. The presence of autoantibodies, such as RF, CCP, C3, C4, ANA, ENA profile, and Anti-dsDNA was documented. For the detection of SLE in IGM patients, we used the SLERPI (SLE risk probability index). Results: A total of 62 patients diagnosed with idiopathic granulomatous mastitis (age 35.22 ± 8.34, BMI 27.15 ± 3.41) were compared to 55 healthy controls (age 32.54 ± 8.67, BMI 26.97 ± 3.54). The present study assessed the performance of SLERPI in IGM, and SLERPI positivity was observed in 12 out of 62 (19.4%) IGM patients. There was a significant difference in arthritis and ANA levels in the SLERPI subgroups (p < 001). Conclusions: The SLERPI index can be utilized to identify patients suspected of having systemic lupus erythematosus (SLE) in the IGM cohort.

Idiopathic Granulomatous Mastitis, Erythema Nodosum, and Polyarthritis

Idiopathic granulomatous mastitis (IGM) is an inflammatory-mediated rare disease that can be linked to rare manifestations. Erythema nodosum (EN) and polyarthritis, seen in a multitude of autoinflammatory and autoimmune diseases, have been rarely linked to IGM. Despite the cause of IGM being unclear, Corynebacterium infections are thought to play a role in the pathophysiology of IGM. Unusually, IGM has a relapsing and remitting course, which also applies to its systemic manifestations. As such, we present a case of IGM in a middle-aged lady who was initially thought to have Corynebacterium-containing unilateral abscesses for which drainage was performed. However, several abscesses devoid of bacterial growth started recurring, and the disease course was complicated by EN and polyarthritis. IGM, EN, and polyarthritis eventually resolved and were managed with symptomatic treatment.

Sarcoidosis Presenting as Granulomatous Mastitis, Erythema Nodosum, and Arthritis Syndrome: A Case Report and Comprehensive Review of the Literature

Granulomatous mastitis (GM) is a long-term inflammatory disease of the breast that usually occurs in women of reproductive age. Autoimmune mastitis is one of the most common pathological breast conditions necessitating tailored treatment. However, GM as a first clinical manifestation of sarcoidosis is uncommon. Simultaneous occurrence of GM, erythema nodosum (EN), and arthritis, termed "GMENA" syndrome, is a rare clinical entity associated with autoimmune rheumatic diseases. Herein, we report the case of a 31-year-old female patient with GMENA syndrome, who presented with a painful nodule of the left breast. Initial treatment entailed antibiotics under the presumption of a breast abscess, yielding negligible improvement. During this period, the patient developed polyarthritis and bilateral EN on the lower extremities. Histopathologic examination of the breast tissue exhibited noncaseating granulomas. The patient responded positively to prednisolone and methotrexate treatment. Literature review revealed a coherent pattern across GMENA cases. Our findings suggest that the "GMENA" syndrome represents a unique acute manifestation of sarcoidosis and highlight the necessity for heightened awareness, accurate diagnosis, and tailored therapeutic approaches for GMENA syndrome. Further research is warranted to elucidate its cause and optimize patient management. This case highlights the importance of identifying and effectively managing such interrelated clinical presentations.

Granulomatous mastitis with erythema nodosum: A breast cancer mimicking entity

We present the case of a 42-year-old Hispanic patient who consulted with a left breast mass that showed clinical and imaging signs of breast cancer. During preprocedural examination before needle biopsy, the patient was found to have bilateral, purplish-brown skin lesions on her lower legs, suggestive of erythema nodosum. This clinical finding raised the diagnostic suspicion of granulomatous mastitis, which was later confirmed by histopathology. Granulomatous mastitis is a rare, nonmalignant entity that should be considered in patients of childbearing age who present with a breast mass. The coexistence with erythema nodosum contributes to the clinical suspicion of granulomatous mastitis; the mechanism of this association and the optimal treatment approach remain unknown.

Idiopathic granulomatous mastitis: clinical, histopathological, and radiological characteristics and management approaches

Idiopathic Granulomatous Mastitis (IGM) is an infrequent, benign breast disease that primarily affects women during their childbearing years and can be mistaken for breast cancer. This study aimed to review the clinical, radiological, and histopathological findings of patients with IGM in addition to management and outcome. Retrospective cross-sectional study of biopsy-confirmed IGM at an academic medical center and a private hospital in Amman, Jordan. Fifty-four patients were included, with a mean age of 37.0 ± 9.04 years, mostly presenting with a breast lump (n = 52, 96.3%) and breast pain (n = 45 patients, 84.9%). Approximately half of the patients (51.9%) were parous, and 50% had breastfed for an average duration of 30.37 ± 22.38 months. Most of the patients had either solitary or multiple abscesses on breast ultrasound. Histopathological analysis (n = 35) showed mostly either moderate inflammation (n = 16, 45.7%) or severe inflammation (n = 14, 40%). Two-thirds of the patients underwent surgical interventions at the time of diagnosis, mostly incision and drainage (n = 16, 29%) or surgical excision (n = 7, 13%), and no mastectomies were performed. The most common medical treatment included a combination of antibiotics, corticosteroids, and methotrexate (n = 21, 38.8%). After follow-up, 31 patients remained in remission, 3 experienced relapses, and 3 had a chronic course. The use of corticosteroids was significantly associated with remission (p = 0.035). The presentation and demographics of IGM patients in Jordan were consistent with the existing literature. Prospective research is needed to explore different treatment options and disease outcomes.

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.

Granulomatous Mastitis Occurring during Pregnancy: A Case Report

Background and Objectives: Granulomatous mastitis is a benign disease with a clinical presentation similar to that of breast cancer, and is most commonly observed in women of childbearing age. Although it has been suggested that autoimmune diseases are involved in its pathogenesis, no specific treatments have been established. The occurrence of this disease during pregnancy has rarely been reported. We presented the case of a 37-year-old woman who complained of left breast induration at 24 weeks' gestation. Materials and Methods: She was pregnant and manifested a dichorionic, diamniotic placenta. At 24 weeks of gestation, the patient experienced a sensation of hardness in her left breast. Mastitis was suspected, and she was treated with cephem antibiotics. Simultaneously, she was diagnosed with erythema nodosum in the extremities. As her symptoms did not improve, an incisional drainage was performed. Bacterial cultures were obtained at 31 weeks of gestation, and Corynebacterium kroppenstedtii was detected. Results: An elective cesarean section was performed at 37 weeks of gestation, and the baby was delivered safely. After delivery, a needle biopsy was performed, and the patient was diagnosed with granulomatous mastitis. She was completely cured with prednisolone after weaning. In this case, the patient's condition was maintained through incision and drainage, as well as antibiotic, anti-inflammatory, and analgesic drugs during pregnancy. This approach was chosen, taking into consideration the potential side effects of steroids. Conclusions: This case suggests that incisional drainage and antibiotic therapy, as well as steroids and surgery, may be considered in the treatment of granulomatous mastitis occurring during pregnancy. This may also be true for management during delivery. After delivery, breastfeeding and steroidal therapy proved to be effective in treating the condition.

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.

Idiopathic Granulomatous Mastitis as an Unusual Cause of Erythema Nodosum in a Malagasy Woman

Introduction

Idiopathic granulomatous mastitis (IGM) is a rare chronic inflammatory disease. Neoplastic and infectious etiologies must be ruled out. IGM is a diagnostic challenge for countries with high tuberculosis endemicity like Madagascar since it may clinically and radiologically mimic breast tuberculosis. We report a case of IGM associated with erythema nodosum in a Malagasy.

Case Report

A 29-year-old primiparous woman came to a dermatological consultation for typical erythema nodosum lesions that appeared one month after a breast swelling. She had no particular medical history. Examination revealed typical erythema nodosum lesions on the legs, voluminous tender mass in the right breast. Bacteriological samples and tuberculosis test were negative. Imaging showed mastitis on the right breast with no evidence of malignancy. Histology revealed a non-caseating granulomas on the lobule of the right breast. As part of an etiological work-up, COVID-19 serology was performed with a positive IgG antibody. The diagnosis of IGM associated with erythema nodosum was evocated. The evolution was favorable under systemic corticosteroid therapy.

Discussion

The cause of this uncommon lesion remains obscure. The extramammary localizations such as erythema nodosum and arthralgia suggest an autoimmune origin. This pathogenesis is also reinforced by a good response to systemic immunosuppression. In our patient, the etiological assessment of the mastitis revealed a chronic infection with SARS-CoV-2. Histopathology is the gold standard for the IGM diagnosis which demonstrates a lobulocentric granulomas without caseous necrosis. Oral corticosteroid therapy is the initial choice of treatment.

Conclusion

Now, with several cases of concomitant IGM and EN reported, dermatologists should be aware that erythema nodosum can be one of the presenting signs of IGM, since the two conditions appear to be associated. The particularity of our case lies in the incidental discovery of SARS-CoV-2 infection. Is a chronic granulomatous disease associated with SARS-CoV-2 infection, a coincidence?

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.

Granulomatous Mastitis With Erythema Nodosum During Pregnancy: A Case Report

Granulomatous mastitis is a rare benign disease that typically occurs in parous women. Some reports have described cases of erythema nodosum appearing following granulomatous mastitis, which is often treated with steroids. Here, we report a case of granulomatous mastitis with erythema nodosum successfully treated via drainage only, which may have been caused by the higher plasma cortisol levels observed during pregnancy. Although mastitis is rare during pregnancy, the current case suggests that granulomatous mastitis should be considered in pregnant women with treatment-resistant mastitis, especially in those with erythema nodosum and a history of birth. Furthermore, patients with granulomatous mastitis may not require prednisolone treatment during pregnancy, which may help in preventing steroid-associated conditions such as infections and gestational diabetes mellitus.

Granulomatous mastitis associated with erythema nodosum: A case series of 42 patients

BACKGROUND

Granulomatous mastitis (GM) is defined by the formation of granulomatous inflammation in breast tissue. Erythema nodosum (EN) is a reactive inflammatory panniculitis characterized by erythematous subcutaneous nodules in the lower limbs. The association of GM with EN has been rarely reported. Our aim was to retrospectively review our series of patients with GM to better characterize their features and their association with EN.

METHODS

Cases histologically diagnosed as granulomatous inflammation in breast tissue between 1995 and 2020 were retrospectively reviewed.

RESULTS

Forty-two women were diagnosed with GM. The average age at diagnosis was 41.619years, and 59.5% were of South-American ethnicity. EN was associated with GM in 11.9% of the patients. Patients with EN were diagnosed earlier than isolated GM (0.4months vs 6.81months; P<.05). Ulceration in the GM was more prevalent in patients with associated EN (60% vs 14.7%; P<.05).

CONCLUSION

EN in patients with GM may reduce the evolution time and may help to diagnose this rare condition that mimics breast carcinoma.

Assertive clinical practice in managing patients with idiopathic granulomatous mastitis: Review of literature

Idiopathic granulomatous mastitis (IGM) is a benign persistent inflammatory breast entity characterized histologically by lobulo centric granulomas. Diagnosis may be difficult and involves a strong index of suspicion. There are plentiful studies are published which render the disease more frequently than expected. The strategy for imaging IGM depends on patient age, clinical manifestations, and risk factors. Patients have an excellent prognosis when they are appropriately treated. The management remains contentious, good judgment is required to ensure optimum treatment form and timing.