Granulomatous Mastitis and Factors Associated with Recurrence: An 11-Year Single-Centre Study of 113 Patients in Singapore

Rare and Complicated Granulomatous Lobular Mastitis (2000-2023): A Bibliometrics Study and Visualization Analysis

Purpose

Granulomatous mastitis (GLM) is a rare and complex chronic inflammatory disease of the breast with an unknown cause and a tendency to recur. As medical science advances, the cause, treatment strategies, and comprehensive management of GLM have increasingly attracted widespread attention. The aim of this study is to assess the development trends and research focal points in the GLM field over the past 24 years using bibliometric analysis.

Methods

Using GLM, Granulomatous mastitis (GM), Idiopathic granulomatous lobular mastitis (IGLM), and Idiopathic granulomatous mastitis (IGM) as keywords, we retrieved publications related to GLM from 2000 to 2023 from the Web of Science, excluding articles irrelevant to this study. Citespace and VOSviewer were employed for data analysis and visualization.

Results

A total of 347 publications were included in this analysis. Over the past 24 years, the number of publications has steadily increased, with Turkey being the leading contributor in terms of publications and citations. The University of Health Sciences, Istanbul University, and Istanbul University Cerrahpasa were the most influential institutions. The Breast Journal, Breast Care, and Journal of Investigative Surgery were the journals that published the most on this topic. The research primarily focused on the cause, differential diagnosis, treatment, and comprehensive management of GLM. Issues related to recurrence, hyperprolactinemia, and Corynebacterium emerged as current research hotspots.

Conclusion

Our bibliometric study outlines the historical development of the GLM field and identifies recent research focuses and trends, which may aid researchers in identifying research hotspots and directions, thereby advancing the study of GLM.

Refractory and Recurrent Idiopathic Granulomatous Mastitis Treatment: Adaptive, Randomized Clinical Trial

BACKGROUND

Idiopathic granulomatous mastitis (IGM) is mostly described as an autoimmune disease with higher prevalence among Middle Eastern childbearing-age women. This study aimed to evaluate the best treatment of choice in patients with resistant or recurrent IGM.

STUDY DESIGN

Patients with established recurrent or resistant IGM who were referred to the Breast Cancer Research Center from 2017 to 2020 were randomly assigned to either one of the following treatment groups: A (best supportive care), B (corticosteroids: prednisolone), and C (methotrexate and low-dose corticosteroids). This adaptive clinical trial evaluated radiological and clinical responses, as well as the potential side effects, on a regular basis in each group, with patients followed up for a minimum of 2 years.

RESULTS

A total of 318 participants, with a mean age of 33.52 ± 6.77 years, were divided into groups A (10 patients), B (78 patients), and C (230 patients). In group A, no therapeutic response was observed; group B exhibited a mixed response, with 14.1% experiencing complete or partial responses, 7.7% maintaining stability, and 78.2% experiencing disease progression. Accordingly, groups A and B were terminated due to inadequate response. In group C, 94.3% achieved complete response, 3% showed partial remission, and 2.7% had no response to therapy. Among the entire patient cohort, 11.6% tested positive for antinuclear antibodies, 3.5% for angiotensin-converting enzyme, and 12.3% for erythema nodosum. Notably, hypothyroidism was a prevalent condition among the patients, affecting 7.2% of the cohort. The incidence of common side effects was consistent across all groups.

CONCLUSIONS

The most effective treatment option for patients with recurrent or resistant IGM is a combination therapy involving steroids and disease-modifying antirheumatic drugs such as methotrexate.

A meta-analysis of idiopathic granulomatous mastitis treatments for remission and recurrence prevention

Purpose

The major aim of our meta-analysis was to review the effectiveness of various treatment modalities for achieving successful remission and preventing recurrence for women with idiopathic granulomatous mastitis (IGM). This knowledge is instrumental in developing evidence-based guidelines for clinicians to improve management strategies and outcomes for patients with IGM.

Methods

A systematic literature search was performed on MEDLINE (Ovid), Embase (Elsevier), PubMed, Cochrane Library, Web of Science, and Google Scholar; studies published to 19 January 2022 were included. A meta-analysis of 57 observational studies was performed. The results of two randomized controlled trials were also examined.

Results

There were 3,035 IGM patients across the observational and randomised studies. Overall recurrence and remission rates across all treatment strategies in 59 studies are 87.9% (2,667/3035) and 13.5% (359/2667), respectively. The studies reported 19 different treatment strategies, comprising observation, medical monotherapies, surgery, and combinations involving medical therapies, with and without surgery. Among monotherapy treatment, surgical management had the highest pooled remission rate (0.99 [95% confidence interval (CI) = 0.97-1.00]); among combination therapy, this was steroids and surgery (0.99 [0.94-1.00]). Antibiotic monotherapy had the lowest remission rate (0.72 [0.37-0.96]). The highest recurrence rates belonged to treatments that combined antibiotics and surgery (0.54 [0.02-1.00]), and antibiotics, steroids, and surgery (0.57 [0.00-1.00]). Most successful for preventing recurrence were observation (0.03 [0.00-0.10]), methotrexate (0.08 [0.00-0.24]), and steroids and surgery (0.05 [0.01-0.12]). There is a significant association between longer follow-up duration and recurrence rate reported, p = 0.002.

Conclusion

Combination therapies, especially those incorporating antibiotics, steroids, and surgery, have demonstrated higher remission rates, challenging the use of antibiotic monotherapy. There is an increased emphasis on the need for personalised, multi-pronged approach for preventing IGM recurrence, with longer follow-up care. More prospective future work in IGM research, with standardised diagnostic criteria, treatment protocols, and reporting guidelines will be important for developing treatment protocols and guidelines clinicians can adhere to in the clinical management of IGM patients.Systematic review registration: PROSPERO (CRD42022301386).

Clinical features and risk factors of bilateral granulomatous lobular mastitis

Granulomatous lobular mastitis (GLM) is an idiopathic inflammatory breast disease that tends to recur on the same side. With the accumulation of clinical cases, it has been observed that GLM can also occur contralaterally. Currently, most studies on GLM focus on treatment methods and risk factors for ipsilateral recurrence, and there are few reports on bilateral GLM. The study aimed to summarize the clinical characteristics of patients with bilateral GLM by reviewing their clinical data, and to discuss the risk factors affecting the occurrence of bilateral GLM. A retrospective study of the medical records database of patients with GLM admitted between May 2019 and August 2022 was performed. Patients were divided into bilateral GLM group (bilateral GLM group) and unilateral GLM patients (unilateral GLM group). Demographic and clinical characteristics, treatment, and follow-up were collected and analyzed. In this study, by reviewing the clinical data of 59 cases of bilateral GLM, we found that the median time between the onset of bilateral GLM on both sides was 6.63 (0-18) months. Additionally, because of the simultaneous or interval onset on both sides, the duration of the disease was longer compared to unilateral cases. Regarding the history of external hospital treatment, it was found that about 57.63% of patients with bilateral GLM received 2 or more treatment modalities, with a higher involvement of herbal medicine. Meanwhile, by counting the clinical data of the 2 groups of patients with bilateral GLM and unilateral GLM, it was shown by univariate analysis that fertility, nipple development, absolute CD4 value, and CD4/CD8 ratio were associated with contralateral onset of GLM in both groups, with inverted nipple being an independent risk factor.

Cystic neutrophilic granulomatous mastitis: sensitivity and specificity of 16s rRNA and Sanger sequencing for Corynebacterium spp

AIMS

Cystic neutrophilic granulomatous mastitis (CNGM) is a subtype of granulomatous mastitis (GM) associated with Corynebacterium spp infection. We aimed to analyse the prevalence of Corynebacteria in CNGM and non-CNGM cases.

METHODS

Breast specimens diagnosed as granulomatous inflammation between 2010 and 2020 were reviewed to identify a CNGM cohort and a non-CNGM cohort. Polymerase chain reaction-based identification of Corynebacteria by 16S ribosomal RNA (16S rRNA) primers, followed by confirmatory Sanger sequencing (SS), was performed on all cases. Clinical, radiological and microbiology data were retrieved from the electronic patient records.

RESULTS

Twenty-eight CNGM cases and 19 non-CNGM cases were identified. Compared with the non-CNGM cohort, patients in the CNGM cohort were more likely to be multiparous (p=0.01), breast feeding (p=0.01) and presenting with a larger breast mass (p<0.01), spontaneous drainage (p=0.05) and skin irritation (p<0.01). No significant difference in the prevalence of Corynebacteria between the cohorts (7% vs 11%, p=0.68) by microbiological culture was identified. Compared with microbiology culture, the sensitivity and specificity of each Corynebacterial detection method were 50% and 81% for Gram stain, and 25% and 100% for 16S rRNA combined with SS. Regardless of the diagnosis, patients positive for Corynebacteria were more likely to have a persistent disease (p<0.01).

CONCLUSION

CNGM presents as a large symptomatic breast mass in multiparous breastfeeding women. The importance of adequate sampling and repeated microbiology culture in conjunction with sequencing on all GM cases with persistent disease is paramount.

Treatment modalities for granulomatous mastitis, seeking the most appropriate treatment with the least recurrence rate: a systematic review and meta-analysis

BACKGROUND

Granulomatous mastitis (GM) is a rare, benign, inflammatory breast disease with an unknown etiology that predominantly affects women of reproductive age. The definitive treatment of GM is currently controversial; an appropriate therapeutic strategy has yet to be identified, and the disease's high recurrence rate remains. This study aims to determine the recurrence rate for each GM treatment strategy to identify the most appropriate treatment modality.

METHODS

The search for relevant articles was undertaken using three international databases, including Medline, Scopus, and Web of Science. Articles published in English until the end of 2021 evaluating the recurrence rate of GM were included. Using Stata 13.0, the pooled incidence and 95% confidence interval (CI) for the recurrence rate were determined.

RESULTS

Sixty-five eligible studies were included in our study. The recurrence rates of systemic steroid use, topical steroid use, antibiotic use, methotrexate use, observation, drainage, excision, antibiotic use and surgery, steroid use and surgery, antibiotic and steroid use, methotrexate and steroid use were 24% (95% CI: 21-27%), 11% (95% CI: 6-21%), 18% (95% CI: 14-22%), 13% (95% CI: 7-22%), 11% (95% CI: 7-17%), 65% (95% CI: 50-78%), 13% (95% CI: 10-16%), 23% (95% CI: 14-36%), 7% (95% CI: 5-11%), 11% (95% CI: 6-18%), and 4% (95% CI: 2-8%), respectively. Drainage had the highest recurrence rate, while combined methotrexate and steroid treatment had the lowest rate.

CONCLUSION

The optimal treatment strategy for GM depends on the disease's severity, consequences, and the patient's features. The study results indicate that combination therapy is preferable for minimizing the risk of relapse and reducing treatment complications.

The Effect of Local Steroid Administration on Idiopathic Granulomatous Mastitis: A Systematic Review andMeta-Analysis

INTRODUCTION

Idiopathic granulomatous mastitis (IGM) is a rare, benign inflammatory breast disease. Corticosteroids and surgery are the primary treatment options, and a growing number of publications have shown the effectiveness of local steroid administration (intralesional injection and topical corticosteroids). However, less is known about the specific details and effects of this treatment approach. The purpose of this meta-analysis was to summarize the details and evaluate the efficacy of local steroid administration for IGM.

METHODS

The PubMed, Embase, Cochrane Library, and SinoMed databases were systematically searched from inception to July 2023 to identify relevant randomized controlled trials. The quality of the included studies was assessed, and meta-analysis and subgroup analysis were conducted to obtain the pooled effect sizes of the outcomes of interest.

RESULTS

Eight trials comprising 613 patients were included. Local steroid administration included intralesional injection and topical steroid ointment, and control groups were mainly given systemic therapy (oral steroid) and surgical treatment. The meta-analysis showed that local steroid administration had a significant effect on the response rate (risk ratio [RR] = 1.35, 95% CI = [1.14-1.59], P = 0.0004). The incidence of side effects was also lower than that of systemic treatment (RR = 0.24, 95% CI = [0.13-0.43], P＜0.0001). There was no difference in the recurrence rate (RR = 0.8, 95% CI = [1.42-1.51], P = 0.48).

CONCLUSIONS

Local steroid administration can increase the RR and decrease the incidence of side effects for IGM patients. There is no significant difference in the recurrence rate between the local steroid administration group and the control group. Further studies are needed to identify the effect in different stages and among pregnant women.

Pathological manifestations of granulomatous lobular mastitis

Granulomatous lobular mastitis (GLM) is a rare inflammatory breast disease with unknown etiology, characterized by non-caseous granulomatous inflammation of the lobules, which infiltrate lymphocytes, neutrophils, plasma cells, monocytes, and eosinophils may accompany. GLM is often misdiagnosed as breast cancer due to the lack of specificity in clinical and imaging examinations, and therefore histopathology is the main basis for confirming the diagnosis. This review provides an overview of the pathological features of granulomatous lobular mastitis and cystic neutrophil granulomatous mastitis (CNGM, a pathologic subtype of GLM). As well as pathologic manifestations of other breast diseases that need to be differentiated from granulomatous lobular mastitis such as breast tuberculosis, lymphocytic mastopathy/diabetic mastopathy, IgG4-related sclerosing mastitis (IgG4-RSM), nodular disease, Wegener's granulomatosis, and plasma cell mastitis. Besides, discusses GLM and CNGM, GLM and breast cancer, emphasizing that their relationship deserves further in-depth exploration. The pathogenesis of GLM has not yet been clearly articulated and needs to be further explored, pathology enables direct observation of the microscopic manifestations of the disease and contributes to further investigation of the pathogenesis.

Predictive Significance of the Preoperative Neutrophil-lymphocyte Ratio for Recurrence in Idiopathic Granulomatous Mastitis Patients

BACKGROUND

To investigate and assess the correlation between inflammatory markers, such as the preoperative neutrophil-lymphocyte ratio (NLR), and the recurrence of idiopathic granulomatous mastitis (IGM).

METHODS

All patients with IGM who were free of malignancy or inflammatory diseases were included in this retrospective analysis between January 2013 and December 2019. On the basis of the presence or absence of recurrence, the patients were split into two groups. After collecting retrospective data, the relationship between patient characteristics, hematological markers such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), NLR, platelet-lymphocyte ratio (PLR), and white blood cell count (WBC), and their connection with postoperative recurrence were assessed utilizing univariate and multivariate analyses, receiver operating characteristic curves (ROC curves), and logistic regression.

RESULTS

Recurrences occurred in 40.0% (32/80) of the 80 patients over a median follow-up duration of 35.5 months (22.0-47.8 months). The recurrent group showed higher NLR and CRP than the non-recurrent group (PNLR = .003, PCRP = .02). Neutrophil-lymphocyte ratio and postoperative recurrence were associated (correlation coefficient r = .436, P = .01). The ROC curve's ideal threshold, which had predictive value for IGM recurrence, was 2.18 (sensitivity: 46.9%; specificity: 14.6%).

CONCLUSION

The preoperative NLR is a simple and affordable way to predict IGM relapse, which is important for directing clinical work.

Framework and guide for intralesional steroid injections in idiopathic granulomatous mastitis

PURPOSE

Literature on how to perform intralesional steroid injections, a valuable therapy for idiopathic granulomatous mastitis (IGM), is limited. This technical note offers a detailed technical guide on intralesional steroid injections for IGM and provides a framework for long-term follow-up.

METHODS

Ultrasound characterization of IGM severity considering breadth, depth, and ancillary findings was used to guide steroid dosing and injection frequency. Clinical and sonographic breast diagrams were designed for accurate longitudinal tracking of IGM. A step-by-step guide for ultrasound-guided IGM aspirations and intralesional steroid injections was developed.

RESULTS

A detailed approach for ultrasound-guided IGM interventions with clinical and sonographic breast diagrams for longitudinal follow-up is now in practice.

CONCLUSIONS

The treatment approach described provides a framework for multidisciplinary treatment of IGM and offers insights that may contribute to the ongoing development and improvement of management strategies for this challenging disease.

Differences and significance of peripheral blood interleukin-6 expression between patients with granulomatous lobular mastitis and those with benign breast tumors

Objective

It is unclear whether the mechanism of the interleukin (IL)-6 signaling pathway is similar between granulomatous lobular mastitis (GLM) and benign breast tumors. This study aimed to explore the differences and significance of peripheral blood IL-6 and related cytokines, routine blood test results, and C-reactive protein (CRP) levels between patients with GLM and benign breast tumors.

Methods

Seventy-three inpatients with GLM who underwent surgery and 60 patients with benign breast tumors diagnosed based on pathological findings between November 2022 and May 2023 were included. The white blood cell (WBC) and neutrophil (NEU) counts were determined using an automatic blood cell analyzer, the CRP level was determined by an immunoturbidimetric assay, and serum IL-6 and related cytokine levels were determined by an enzyme-linked immunosorbent assay.

Results

The WBC, NEU, and CRP values in patients with GLM were significantly higher than those in patients with benign breast tumors (P < 0.01). Serum IL-6 levels were significantly higher in patients with GLM than in those with benign breast tumors (P < 0.01). There were no significant differences in the serum concentrations of IL-1β, IL-7, and interferon (IFN)-γ between patients with GLM and those with benign breast tumors (P > 0.05), but the tumor necrosis factor (TNF)-α level was higher in patients with GLM than in those with benign breast tumors (P < 0.01). In patients with GLM, the Pearson correlation analysis showed that the IL-6 level was positively correlated with NEU, NEU%, CRP, IL-17, and TNF-α values (P < 0.01). Additionally, the IL-6 level was weakly positively correlated with WBC and IFN-γ values. Conversely, in patients with benign breast tumors, the IL-6 level was not significantly correlated with the aforementioned indicators in routine blood tests but was positively correlated with IL-17, IFN-γ, and TNF-α values (P < 0.01).

Conclusions

IL-6, NEU, NEU%, and CRP values were significantly elevated in patients with GLM compared to those with benign breast tumors, indicating that IL-6 plays an important role in the development and onset of GLM. The correlation between these cytokines and the development and progression of benign breast tumors needs to be further explored, as cytokines such as IL-6 may provide effective markers for the treatment of GLM.

Efficacy of preoperative Shugan Sanjie decoction combined with mammotome-assisted minimally invasive surgery in the treatment of idiopathic granulomatous mastitis: A retrospective cohort study

The management of idiopathic granulomatous mastitis (IGM) poses a significant challenge because of its ambiguous etiology. This study aimed to investigate the efficacy of traditional Chinese medicine (TCM) combined with mammotome-assisted minimally invasive surgery (MAMIS) for the treatment of IGM. This retrospective cohort study included patients with IGM who underwent treatment at our hospital between January 2017 and June 2022. Patients treated with Shugan Sanjie decoction alone and preoperative Shugan Sanjie decoction combined with MAMIS were included in Groups A and B, respectively. We focused on the demographics, clinical characteristics, and outcomes of the patients in the 2 groups. A total of 124 female patients with an average age of 33.9 ± 3.6 years were included in the study. The demographic and clinical characteristics of patients in Groups A (n = 55) and B (n = 69) were similar (P > .05). However, there were significant differences between the 2 groups in terms of treatment duration, 1-year complete remission (CR), and recurrence. Group B showed shorter treatment time (11.7 ± 5.1 vs 15.3 ± 6.4 months, P = .001), higher 1-year CR (72.5% vs 45.5%, P = .002), and lower recurrence (7.2% vs 21.8%, P = .019) in comparison to Group A. Shugan Sanjie decoction promoted the shrinkage of breast lesions in patients with IGM. Combined with MAMIS, this treatment regimen shortened the treatment duration, accelerated the recovery process, and reduced the recurrence rate.

Combining intralesional steroid injection with oral steroids in patients with idiopathic granulomatous mastitis

Idiopathic granulomatous mastitis (IGM) is a chronic inflammatory breast disease. Currently, there is no international standard for steroid use in IGM, particularly for intralesional steroid injections. This study aimed to determine whether patients with IGM who received oral steroids could benefit from intralesional steroid injection. We analyzed 62 patients with IGM whose main clinical presentation was mastitis masses and who received preoperative steroid therapy. Group A (n = 34) received combined steroid treatment: oral steroids (starting dose, 0.25 mg/kg/d; tapered off) and intralesional steroid injection (20 mg per session). Group B (n = 28) received oral steroids only (starting dose, 0.5 mg/kg/d; tapered off). Both groups underwent lumpectomy at the end of steroid treatment. We analyzed the preoperative treatment time, preoperative mass maximum diameter reduction rate, side effects, postoperative satisfaction, and rate of IGM recurrence. The mean age of the 62 participants was 33.6 ± 2.3 (range, 26-46) years, and all had unilateral disease. We found that oral steroids combined with intralesional steroid injection yielded better therapeutic effects than did oral steroids alone. The median maximum diameter reduction of the breast mass was 52.06% in group A and 30.00% in group B (P = .002). Moreover, the use of intralesional steroids reduced the duration of oral steroid use; the median durations of preoperative steroid therapy were 4 and 7 weeks in groups A and B, respectively (P < .001). Group A patients were more satisfied (P = .035) with the postoperative results, including postoperative appearance and function. No statistically significant between-group differences were noted regarding side effects and recurrence rates. Preoperative administration of oral steroids combined with intralesional steroid injection yielded better therapeutic effects than did oral steroids alone and may be an effective future treatment for 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.

Risk Factors and the Role of the Albumin-to-Globulin Ratio in Predicting Recurrence Among Patients with Idiopathic Granulomatous Mastitis

Background

Idiopathic granulomatous mastitis (IGM) is a rare inflammatory disease of the breast with a high recurrence rate. The serum albumin to globulin ratio (AGR) is a relatively novel biomarker in inflammatory diseases, and one whose role in the recurrence of IGM remains unknown. This study primarily investigated the potential risk factors for IGM recurrence and whether AGR can be used as a predictive factor.

Methods

Patients diagnosed with IGM from pathology reports between 2016 and 2021 were enrolled in the study, and their medical records were analyzed retrospectively. The patients were divided into two groups – recurrence and non-recurrence. Clinical, demographic characteristics, and laboratory parameters were compared.

Results

Eighty-five patients were included in the study, recurrence being detected in 16 (18.8%) of these, with a median follow-up time of 39.99±18.93 months. No relationship was determined between childbearing, breastfeeding, disease severity, or therapeutic approaches and IGM recurrence. While AGR was significantly lower in the recurrence group (p < 0.001), neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) results were comparable in the two groups (p = 0.472 and p = 0.421, respectively). Multivariate analysis identified low AGR (odds ratio (OR): 50.7, 95% CI 5.93–434.1 P < 0.001) and smoking (OR: 4.45, 95% CI 1.04–18.9 P = 0.044) as independent risk factors for IGM recurrence.

Conclusion

The study findings indicated that AGR at a cut-off value of ≤1.179 at diagnosis and smoking exhibited a remarkable performance in predicting the recurrence of IGM. Developing new risk stratification systems for IGM recurrences and using AGR in these classifications may increase the success of treatment.

Trial Registration

This study was registered with ClinicalTrials.gov, NCT05409586.

Management of Granulomatous Lobular Mastitis and Risk Factors Associated with Recurrence

BACKGROUND

Granulomatous lobular mastitis (GM), an inflammatory breast lesion with unknown etiology, is prone to recur. There is no global consensus on the optimal treatment at present. This study was conducted to show our step-by-step systemic procedure and discuss the recurrence risk factors of GM.

METHODS

The medical record database was retrospectively searched for patients with GM treated in our hospital between January 2015 and September 2021. Patients were divided into non-recurrence group (group A) and recurrence group (group B). Demographic and clinical characteristics, treatment and follow-up were collected and analyzed.

RESULTS

A total of 885 GM patients were included in our study, all of whom received step-by-step systemic management. The mean age was 33.2 ± 5.2 years. There were 760 (85.9%) patients in group A and 125 (14.1%) in group B. Univariate analysis showed that there was no statistically significant difference between the two groups in size of mass, pregnancy, hyperprolactinemia, bacterial cultures, erythema nodosum. Multivariate analysis showed that patients with purulent nipple discharge, skin lesion, bilateral disease and patients who need the combination of surgery and medication to achieve complete remission had higher risk of recurrence.

CONCLUSIONS

We built a step-by-step systemic procedure for GM, and the recurrence rate was 14.1%. Prolactin level and microbiological results are important for the management of GM. Purulent nipple discharge, skin lesion, bilateral disease and patients who need the combination of surgery and medication to achieve complete remission are associated with GM recurrence. Prolonged maintenance therapy may secure a better prognosis.

A case management model for patients with granulomatous mastitis: a prospective study

Background

Granulomatous mastitis (GM) is a chronic inflammatory mastitis disease that requires long-term treatment and has a high recurrence rate. Case management has been proven to be an effective mechanism in assisting patients with chronic illness to receive regular and targeted disease monitoring and health care service. The aim of this study was to investigate the application of a hospital-to-community model of case management for granulomatous mastitis and explore the related factors associated with its recurrence.

Methods

This was a prospective study on patients with granulomatous mastitis based on a case management model. Data on demographic, clinical and laboratory information, treatment methods, follow-up time, and recurrence were collected and analyzed. The eight-item Morisky Medication Adherence Scale (MMAS-8) was used to investigate patients' adherence to medications. Logistic regression models were built for analysis of risk factors for the recurrence of granulomatous mastitis.

Results

By October 2021, a total of 152 female patients with a mean age of 32 years had undergone the entire case management process. The mean total course of case management was 24.54 (range 15–45) months. Almost all the patients received medication treatment, except for one pregnant patient who received observation therapy, and approximately 53.9% of the patients received medication and surgery. The overall recurrence rate was 11.2%, and “high” medication adherence (RR = 0.428, 95% CI 0.224–0.867, P = 0.015) was significantly associated with a lower rate of recurrence, while the rate of recurrence with a surgical procedure + medication was higher than that with medication alone (RR = 4.128, 95% CI 1.026–16.610, P = 0.046).

Conclusion

A case management model for patients with granulomatous mastitis was applied to effectively monitor changes in the disease and to identify factors associated with disease recurrence. “Low” medication adherence was a significant risk factor for the recurrence of granulomatous mastitis. Patients treated with medication and surgery were more likely to experience recurrence than those treated with medication alone. The optimal treatment approach should be planned for granulomatous mastitis patients, and patient medication adherence should be of concern to medical staff.

Management of granulomatous lobular mastitis: an international multidisciplinary consensus (2021 edition)

Granulomatous lobular mastitis (GLM) is a rare and chronic benign inflammatory disease of the breast. Difficulties exist in the management of GLM for many front-line surgeons and medical specialists who care for patients with inflammatory disorders of the breast. This consensus is summarized to establish evidence-based recommendations for the management of GLM. Literature was reviewed using PubMed from January 1, 1971 to July 31, 2020. Sixty-six international experienced multidisciplinary experts from 11 countries or regions were invited to review the evidence. Levels of evidence were determined using the American College of Physicians grading system, and recommendations were discussed until consensus. Experts discussed and concluded 30 recommendations on historical definitions, etiology and predisposing factors, diagnosis criteria, treatment, clinical stages, relapse and recurrence of GLM. GLM was recommended as a widely accepted definition. In addition, this consensus introduced a new clinical stages and management algorithm for GLM to provide individual treatment strategies. In conclusion, diagnosis of GLM depends on a combination of history, clinical manifestations, imaging examinations, laboratory examinations and pathology. The approach to treatment of GLM should be applied according to the different clinical stage of GLM. This evidence-based consensus would be valuable to assist front-line surgeons and medical specialists in the optimal management of GLM.

Idiopathic granulomatous mastitis: introducing a diagnostic algorithm based on 5 years of follow-up of 152 cases from Turkey and a review of the literature

PURPOSE

The goals of this study were to report our clinical experience in a single center at a high-volume tertiary university hospital in Istanbul and to introduce a diagnostic algorithm based on a 5-year follow-up of 152 women with biopsy-proven idiopathic granulomatous mastitis (IGM). IGM is an uncommon, non-malignant, chronic inflammatory disease of the mammary gland with an unknown etiology. The symptoms, clinical presentation, and radiologic findings of IGM may resemble carcinomas. To our knowledge, this study comprises the largest series of IGM, especially with a 5-year follow-up, yet reported in the English literature.

METHODS

The present study reported our single-center clinical experience at a tertiary university hospital in Istanbul, Turkey, and introduced a diagnostic algorithm using our treatment protocol based on a 5-year follow-up of 152 women with biopsy-proven IGM. Our database of 10 years' experience containing over 700 patients with IGM was evaluated. However, to assess recurrence and resistance to treatment, only the 152 patients with a long follow-up period of 5 years were included in the study group. The analysis included 152 women with biopsy-proven IGM who were treated between January 2009 and March 2014. The clinical data of the presentation, histopathology, and treatment modalities were analyzed by reviewing the medical records.

RESULTS

Of the 152 patients diagnosed with granulomatous mastitis, 32 (21%) recovered by expectant management, while 14 (9%) responded to antibiotics, 65 (43%) received corticosteroids, 20 (13%) had antituberculosis medication, 16 (11%) underwent excision, and 5 (3%) responded to non-steroidal anti-inflammatory drugs. Fifty-one patients (33%) had recurrence; of these, 30 achieved a cure with second-line treatment, 16 underwent excision, and 5 achieved a cure with observation.

CONCLUSION

IGM is a rare benign breast disorder, and clinicians need a high index of suspicion to diagnose it, as IGM can be mistaken for breast cancer. Unlike periductal mastitis, IGM does not evolve secondary to nicotine addiction and is typically seen in women of childbearing age with a recent history of pregnancy and lactation. The diagnosis can be challenging, and an evaluation with a multidisciplinary team is necessary. There is no consensus concerning the definitive treatment approach. We suggested a diagnostic algorithm in the present study, using our treatment protocol based on the 5 years' follow-up of 152 women.

Clinicopathological evaluation of idiopathic granulomatous mastitis patients: A retrospective analysis from a tertiary care hospital in Turkey

Idiopathic granulomatous mastitis (IGM) is a chronic inflammatory disease of the breast with unknown etiology that is characterized by granuloma formation. We analyzed the clinical, radiological, and therapeutic approaches; the recurrence rate of the disease; and the pathological findings diagnosed with mastitis in a retrospective study. We evaluated a total of 77 patients subjected to core needle or excisional biopsy with preliminary diagnosis of mastitis between January 2017-December 2019 who diagnosed with IGM, nonspecific mastitis/abscess, or periductal mastitis/plasma cell mastitis as a result of their pathological assessment. The mean age was 39.24 ± 10.6. Though 65 patients were diagnosed with IGM (84.4%), other diagnoses were reported as nonspecific mastitis/abscess (n = 9), periductal mastitis (n = 2) and plasma cell mastitis (n = 1). Recurrence occurred in 30 (39%) patients during follow-up. In patients without IGM, the number of 5-year postpartum mastitis diagnoses was significantly higher (p = 0.0008) while number of 2-year postpartum mastitis diagnoses was lower (p = 0.255) compared to those in IGM patients. The rates of axillary lymphadenopathy, bacterial culture, parity, and menopausal status were not different in patients without IGM. Linear correlation analysis did not reveal a significant relationship between radiological preliminary diagnosis and pathological diagnosis with BI-RADS classification. A detailed assessment, accompanied with clinical, radiological, and pathological findings, should be performed to achieve an accurate diagnosis and effective patient management in IGM. Furthermore, IGM should always be considered in the differential diagnosis of mastitis among breast masses.

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.

Postoperative Yanghe decoction regimen improves outcomes for idiopathic granulomatous mastitis: A retrospective cohort study

The etiology of idiopathic granulomatous mastitis (IGM), a rare inflammatory breast disease, is not understood. There is no consensus regarding the treatment of IGM. The purpose of this study was to determine the efficacy of surgery combined with traditional Chinese medicine for the treatment of IGM.We retrospectively analyzed 53 patients of IGM who were treated with surgical excision at our hospital. Group A (n = 25) included patients treated with only surgery, and Group B included patients treated with surgery combined with postoperative Yanghe decoction. The clinical data were compared between the 2 groups, including demographics, clinical characteristics, and outcomes.All patients were female with a mean age of 34.6 ± 5.9 years. There were no significant differences between the groups regarding preoperative demographics or clinical characteristics. The follow-up time was comparable between the groups (13.2 ± 10.0 vs 12.0 ± 10.2 months). Patients in Group B had shorter complete remission (CR) times than patients in Group A (76.1 ± 15.2 vs 84.0 ± 12.2 days; P < .05). The CR rate was higher in Group B than in Group A (96.4% vs 76.0%; P < .05), and the recurrence rate was lower in Group B than in Group A (0% vs 16.0%; P < .05).The postoperative Yanghe decoction regimen was associated with more rapid recovery after IGM surgery. Surgical management combined with postoperative oral Yanghe decoction treatment yielded a higher CR rate and lower recurrence rate than surgery alone. The effect of traditional Chinese medicine in IGM treatment requires further study.

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.

Cystic Neutrophilic Granulomatous Mastitis: A Clinicopathological Study With 16s rRNA Sequencing for the Detection of Corynebacteria in Formalin-Fixed Paraffin-Embedded Tissue

Cystic neutrophilic granulomatous mastitis (CNGM) is a histologically characterized variant of granulomatous lobular mastitis that is associated with lipophilic Corynebacterium species. It remains a largely underrecognized entity in India. Our aim was to study CNGM in the Asian Indian population and explore if 16s rRNA sequencing could be used on formalin-fixed paraffin-embedded (FFPE) tissue to identify the causative organism. We studied 24 cases with histological features of CNGM with hematoxylin and eosin, Gram, Ziehl-Neelsen, and Periodic acid-Schiff stains. Tuberculosis-polymerase chain reaction and 16s rRNA gene sequencing on DNA extracted from FFPE was attempted (N = 23). Gram-positive bacilli were seen in 20/24 cases. Routine culture with prolonged incubation yielded Corynebacterium species in 8 cases; 7 of these cases were evaluated by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for species identification. C matruchotti was identified in one case by BD Phoenix. MALDI-TOF MS identified the remaining 7 cases as C kroppenstedtii (N = 4) and C tuberculostearicum (N = 2), with no identification in one. Corynebacteria were identified by 16s rRNA sequencing on DNA extracted from FFPE in 12/23 cases using a primer targeting the V5-V6 region that was found to be more conserved in Corynebacterium species. All cases were negative for the diagnosis of tuberculosis. CNGM can be identified by routine stains. Culture using routine media with prolonged incubation is often adequate to isolate the organism. 16s rRNA sequencing on DNA extracted from FFPE tissue can help make an etiological diagnosis in some cases where only paraffin blocks are available.