Granulomatous mastitis: is it an autoimmune disease? Diagnostic and therapeutic dilemmas

Idiopathic granulomatous mastitis: A challenging case report and comprehensive review of the literature

INTRODUCTION AND IMPORTANCE

Idiopathic granulomatous mastitis is an uncommon, long-lasting inflammatory condition of the female breast. It is characterized by the development of a painful breast mass that gradually increases in size. This condition is benign and its cause is unknown. It primarily affects women of childbearing age who have a history of pregnancy and breastfeeding. The main feature of idiopathic granulomatous mastitis is the presence of chronic inflammation in the breast.

CASE PRESENTATION

We report a 36-year-old woman with a history of pregnancy and breastfeeding presented with pain and swelling of the right breast. Physical examination revealed a mass with redness and retraction of the nipple. Imaging revealed localized density and hypoechoic areas with collection, suggesting granulomatous mastitis. A biopsy confirmed the diagnosis. The abscess was drained through a small incision performed under local anesthesia. Treatment with corticosteroids resulted in significant improvement, with complete resolution after one month.

CLINICAL DISCUSSION

A comprehensive evaluation of potential causes is necessary to confirm the diagnosis of idiopathic granulomatous mastitis. Histologically, it is distinguished by the predominant presence of neutrophils and the absence of caseous necrosis. Treatment remains controversial, with recent literature supporting the efficacy of conservative management with steroid and immunosuppressive therapy, leaving surgical excision for complicated and refractory cases.

CONCLUSIONS

Idiopathic granulomatous mastitis is an uncommon breast condition where the exact causes and recommended treatment approaches are not well-defined. It is important to consider this condition in women who are in their reproductive years.

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.

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.

Local steroid injection in severe idiopathic granulomatous mastitis as a new first-line treatment modality with promising therapeutic efficacy

Background

Intralesional steroid injection has recently evolved as a novel treatment modality for localized idiopathic granulomatous mastitis (= IGM). We aimed to explore the therapeutic efficacy of local steroid injections (LSI) in patients with severe IGM.

Methods

Fifty-one patients diagnosed with severe IGM were included in the study and treated with either local steroid injection (LSI) alone (n = 25) or combined LSI with systemic oral steroid treatment (OST) (n = 26). The local steroid injection protocol included an intralesional triamcinolone acetonide injection into the palpable granulomas every 4-week, and topical administration of steroid-containing pomades twice a day on the affected surface of the breast. Patients with a combined LSI and OST received low-dose oral methylprednisolone (<16 mg).

Results

Patients with LSI alone required more LSI applications than those in the combined LSI with OST group (LSI: 5 ± 2.9; vs. LSI/OST: 3.5 ± 2.5; p = 0.080) to obtain an effective optimum therapeutic response. At a median of 12 months (range, 4-42), no difference was found in complete response rates between patients in the LSI group and the combined LSI group with OST (52 vs. 53.9%, p = 0.999). However, steroid-related systemic side effects were lower in the LSI alone group (p < 0.008).

Conclusion

Local steroid injection could be considered as the first-line treatment in patients with severe IGM until a therapeutic response has been obtained either as the sole treatment modality or combined with oral steroids. Compared with systemic oral steroid therapy, local steroid administration can be considered a new treatment modality with fewer side effects.

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.

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.

A Rare Case of Granulomatous Mastitis Associated With Positive Systemic Lupus Erythematosus Serology in a Young Female Patient: A Case Report and Literature Review

Granulomatous mastitis (GM) is a rare benign breast disease that affects women of childbearing age, usually within five years of pregnancy. The hallmark diagnostic feature of GM is the presence of lobular granulomatous inflammation. The occurrence of this clinicopathological entity is usually idiopathic. Nevertheless, GM has often been associated with systemic inflammatory conditions of either infectious (such as tuberculosis) or autoimmune etiology (particularly sarcoidosis, vasculitis, and less likely systemic lupus erythematosus [SLE]). In this report, the authors described an unusual case of GM that was associated with features of SLE in a young female patient who presented with a painful breast lump. Histopathological examination of the lump's biopsy showed GM. Further laboratory workup revealed evidence of some immunological criteria of SLE. Steroid therapy led to the resolution of the patient's breast swelling. The breast mass remained in remission with hydroxychloroquine treatment. Only a handful of similar cases in the current literature demonstrated a plausible association between SLE and GM. Our case provides a reference to consider SLE as a possible differential diagnosis when GM is encountered in young-aged female patients.

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?

The efficacy of St John's wort oil macerates on intractable skin lesions of patients with idiopathic granulomatous mastitis: preliminary results

Objective:

St John's wort (SJW, Hypericum perforatum) has a long history of medicinal use, mainly for its antidepressive effects and for wound healing. However, to the best of our knowledge, this is the first clinical study evaluating the effects of topical SJW oil macerates on the intractable skin lesions of idiopathic granulomatous mastitis (IGM).

Method:

SJW oil massage (twice daily for two minutes) was recommended between 2016 and 2019, only for patients with persistent or intractable skin lesions, after complete regression of granulomatous mass with two cycles of high-dose oral steroid and empiric antibiotics. Skin lesions were assessed and graded, before and after treatment, as clear, mild, moderate and severe. A questionnaire was also completed for each patient at the end of the six-week treatment.

Results:

A total of 21 patients with persistent IGM lesions used SJW oil after completion of the standard treatment protocol. All patients were women, and the mean age was 36.6 years. Hyperaemia (100%), scaling (61%), induration (52%) and ulcers (28%) were the predominant skin lesions. Distribution of the lesions according to the degree of severity were graded mild, moderate and severe, and seen in 35%, 41% and 23% of the patients, respectively. When compared with pre-treatment scores, there were very significant regressions (clear: 76.4%, mild: 17.6%, moderate: 3.9%, severe: 1.9%; p<0.001 for each). The overall success rate (total clearance or decrease/decline in lesions) of treatment was 94%.

Conclusion:

SJW oil massage seems to be very effective in patients with IGM-related persistent skin lesions.

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.

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.

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.

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.

Granulomatous mastitis, erythema nodosum, and polyarthritis: a case report

BACKGROUND

Granulomatous mastitis is a rare inflammatory disease of the breast, typically seen in woman of child-bearing age. No definitive etiology has been described. In rare instances, this condition has been reported to be associated with extramammary manifestations such as erythema nodosum and arthritis. We describe this rare condition in an adolescent female.

CASE PRESENTATION

A 16-year-old, Hispanic female presented with right-sided painful breast swelling, polyarthritis, and erythema nodosum on bilateral shins and lower thighs. Physical examination was negative for lymphadenopathy and pulmonary, gastrointestinal, and cardiovascular findings. Ophthalmologic examination for uveitis and serologic tests for autoimmune diseases were negative. Diagnosis of idiopathic granulomatous mastitis was made by exclusion of other etiologies and conditions. Confirmation was made by histopathologic examination demonstrating noncaseating granuloma within breast lobules with neutrophils and microabscess formation. After wide local excision and a short course of trimethoprim-sulfamethoxazole, our patient was placed on naproxen and prednisone, the latter being tapered off over 3 months, with steady and complete resolution of all symptoms.

CONCLUSION

This is the first reported case of idiopathic granulomatous mastitis in a pediatric patient who also had extramammary manifestations, including erythema nodosum and polyarthritis. In this case-based review, we summarize the phenotype, risk factors, prognosis, and treatment options of this rare condition, chiefly to make the readers cognizant of such a diagnostic possibility in similar clinical presentation in the future.

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.

Idiopathic granulomatous mastitis: case series and clinical review

Idiopathic granulomatous mastitis is a chronic inflammatory breast disorder that typically affects young, parous women, often following lactation. Patients present with tender, erythematous breast lesions with histological evidence of non-caseating granulomata and an inflammatory cell infiltrate. An immune-mediated pathophysiology is hypothesised and an association with lipophilic Corynebacterium species is observed. Initial diagnosis is often delayed due to lack of awareness of the condition and management of refractory disease can be challenging. We present an extensive case series of patients collaboratively managed by subspecialty physicians and surgeons at a single centre in Sydney, Australia. The accompanying review expands on features of this condition and supports the utility of a multidisciplinary approach.

A novel therapy for granulomatous lobular mastitis: Local heat therapy

Granulomatous lobular mastitis (GLM) is a chronic inflammatory breast condition that is characterized by granulomatous inflammation. GLM remains a refractory disease due to its failure to respond to routine anti-inflammatory therapies and its high recurrence rate. Thus, the present study aimed to investigate the application of local heat therapy in GLM as a potential therapeutic strategy. The results revealed that the application of local heat therapy was associated with a shortened remission time for GLM, while the remission and recurrence rates were similar to those of existing therapies. The median first remission time following local heat therapy was significantly decreased compared with that following corticosteroid therapy (5.30 months vs. 11.27 months; P<0.05). The remission rates were not significantly different between the local heat therapy (76.9%), extensive excision (90.4%) and the corticosteroid therapy (85.7%) groups (P>0.05). In addition, the recurrence rates were not statistically different between the groups (local heat therapy, 8.3%; extensive excision, 10%; and corticosteroid therapy, 10%; P>0.05). The local heat therapy showed mild adverse effects and shortened healing times compared to the other therapies; however, further confirmation is required.

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

BACKGROUND

Idiopathic Granulomatous Mastitis (IGM) is a benign chronic inflammatory breast disease that mimics breast cancer, and the etiopathogenesis has not yet been fully evaluated. Autoimmunity has received the most focus as a possible etiology. Our aim in this prospective clinical study was to investigate the possible association between the cytokines, interleukin IL-17, IL-22, IL-23 and IGM.

MATERIALS AND METHODS

The current study was conducted in 26 women with histopathologically diagnosed IGM, and 15 control women of reproductive age having no breast disease history. Blood samples were collected, and serum concentrations of IL-17, IL-22, and IL-23 were determined.

RESULTS

In the analysis of variables, the patients with IGM and the control group had statistically significant differences between serum IL-22 titers (p = 0.0378) and IL-23 titers (p = 0.0469. No statistically significant difference was found between IGM patients and the control group in serum IL-17 titers (p = 0.9724).

CONCLUSION

The results of the current study, especially pertaining to serum IL-22 and IL-23 levels, support the etiopathogenesis of IGM in favor of the autoinflammatory thesis. Nevertheless, this thesis should be supported by a large case number and prospective clinical studies.

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.

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.

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.

Severe idiopathic granulomatous mastitis treated with systemic medication; A case report

Idiopathic granulomatous mastitis is a benign chronic inflammatory breast disease and a confused treatment plan may result in worsening of the disease, unacceptable cosmetic damage for the patient and even mastectomy. We report a case of a 39-year-old Chinese woman with a two-month history of painful, solid, diabrotic, left breast lesions that measured 10 × 15 cm. Misdiagnosis had led to delayed wound healing with extensive ulcerative skin lesions. The patient was successfully treated with oral corticosteroids and bromocriptine without requirement for surgery.

Is There any Relationship Between Granulomatous Mastitis and Seasons? An Analysis of Seasonal Frequency, Clinical, and Radiologic Findings

Objective

Idiopathic granulomatous mastitis (IGM) is a rare, resistant, and recurrent benign disease of the breast. IGM can be clinically and radiologically confused with breast carcinoma, and core needle biopsy is needed to diagnose. The etiology and pathogenesis of IGM have not been fully explained. This premenopausal disease may be associated with pregnancy, breastfeeding, autoimmune processes, inflammation, and oral contraceptives. However, there is no study on whether there is a seasonal relationship.

Materials and Methods

From January 2015 to January 2020, the seasonal relationship of IGM was evaluated in 37 females aged between 25-49.

Results

Although all cases were distributed between September and May, there was no statistically significant result in the relationship with the season. US is the main modality in the diagnosis of this condition which only provides an accurate pre-diagnosis approach with the typical USG appearance features. Some MRI features may help us to distinguish IGM from breast malignities.

Conclusion

IGM is a rare chronic non-specific inflammatory lesion of the breast, which can be confused with benign and malignant breast diseases in both clinical and radiologic aspects. To understand the etiology of this condition better, the seasonal connection needs to be evaluated in larger patient groups.

Idiopathic granulomatous mastitis: Management and predictors of recurrence in 474 patients

Idiopathic Granulomatous Mastitis (IGM) is an uncommon inflammatory disease of the breast, with similar presentations as breast cancer and a relatively high recurrence rate. We reviewed the demographics, clinical presentations, and treatment modalities of a large cohort of patients in Iran. Most of the patients had history of pregnancy and breastfeeding. The most common clinical finding was pain and a palpable mass, respectively. Most of the patients received medical treatment, and about half of the patients had surgery. The recurrence rate was 24.8%, and breast skin lesions were associated with a significantly higher odds of recurrence.

Mastitis in Autoimmune Diseases: Review of the Literature, Diagnostic Pathway, and Pathophysiological Key Players

Mastitis frequently affects women of childbearing age. Of all the pathological breast conditions requiring specific management, autoimmune mastitis is in the third position after infection and breast cancer. The aim of this literature review was to make a comprehensive description of autoimmune diseases targeting the mammary gland. Four main histological patterns of autoimmune mastitis are described: (i) lymphocytic infiltrates; (ii) ductal ectasia; (iii) granulomatous mastitis; and (iv) vasculitis. Our literature search found that all types of autoimmune disease may target the mammary gland: organ-specific diseases (diabetes, thyroiditis); connective tissue diseases (such as systemic erythematosus lupus or Sjögren’s syndrome); vasculitides (granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, giant cell arteritis, polyarteritis nodosa, Behçet’s disease); granulomatous diseases (sarcoidosis, Crohn’s disease); and IgG4-related disease. Cases of breast-specific autoimmune diseases have also been reported, including idiopathic granulomatous mastitis. These breast-limited inflammatory diseases are sometimes the first symptom of a systemic autoimmune disease. Although autoimmune mastitis is rare, it is probably underdiagnosed or misdiagnosed. Early diagnosis may allow us to detect systemic diseases at an earlier stage, which could help to initiate a prompt, appropriate therapeutic strategy. In case of suspected autoimmune mastitis, we hereby propose a diagnostic pathway and discuss the potential pathophysiological pathways leading to autoimmune breast damage.

Cystic neutrophilic granulomatous mastitis: an update

Cystic neutrophilic granulomatous mastitis (CNGM) is a rare subtype of granulomatous mastitis with a highly distinct histological pattern often associated with Corynebacterium species. CNGM is characterised by suppurative lipogranulomas that are composed of central lipid vacuoles rimmed by neutrophils and an outer cuff of epithelioid histiocytes. Some of the lipid vacuoles may contain sparse, rod-shaped, gram-positive bacilli that can be easily missed or dismissed. The surrounding mixed inflammatory infiltrate contains Langhans-type giant cells, lymphocytes and neutrophils. CNGM occurs in reproductive age women with a history of pregnancy and typically presents as a palpable mass that can be painful. CNGM has many mimickers, most significantly breast carcinoma. In many cases, CNGM has significant pathological and clinical overlap with other forms of granulomatous mastitis. Given the association with Corynebacterium species, early diagnosis of CNGM is essential in offering patients the most appropriate treatment. Prolonged antibiotic therapy specifically directed to corynebacteria is required, sometimes even beyond resolution of clinical symptoms. This comprehensive review of the existing literature on CNGM describes clinical-pathological features, microbiological findings, challenges associated with the microscopic differential diagnosis, clinical implications of this diagnosis and emerging treatment options. Morphological criteria and suggested comments to convey the degree of diagnostic certainty are also proposed for standard pathology reporting.

The clinical value of interleukins-8, -10, and -17 in idiopathic granulomatous mastitis

INTRODUCTION

Idiopathic granulomatous mastitis (IGM) is a rare, chronic inflammatory benign breast disease. Although the etiology of this disease is unknown, it has been suggested that hormonal disorders, autoimmunity, smoking, and α1-antitrypsin deficiency may play a role in the etiopathogenesis. The aim is to investigate the changes in cytokine profiles including interleukin (IL)-4, -8, -10, -17, and tumor necrosis factor (TNF)-alpha in patients with IGM.

METHODS

Forty-seven patients with pathologically diagnosed IGM and 30 healthy women were included. The cytokines including IL-4, -8, 10, -17, and TNF-alpha were measured by human enzyme-linked immunosorbent assay.

RESULTS

The IL-8, IL-10, and IL-17 levels were higher in IGM patients than control group (p = .002; p = .008; and p = .018, respectively). The IL-8 levels of patients with active lesions and in remission were statistically higher than the control group (p = .027 and p = .015, respectively). IL-10 levels of patients in remission were higher than the control group (p = .024). There was no difference in IL-4 and TNF-ɑ levels between all groups.

CONCLUSION

These results showed that proinflammatory cytokines including IL-8 and IL-17 have role in pathogenesis of IGM. However, the increased levels of IL-10 in especially patients in remission suggest that it reduces the release of proinflamatory cytokines as well as suppressing their function and activation for controlling IGM. Although IGM is thought to be a surgical disease, these cytokine changes indicate the presence of serious immune dysregulation. This suggests that in the treatment of IGM, treatment needs to evolve from surgery to medical treatment.Key points• The IL-8, IL-10, and IL-17 levels were higher in IGM patients than in control group.• The IL-8 levels of both patients with active lesions and in remission were high.• There was no difference in IL-4 and TNF-ɑ levels between all groups.

The Predictive Value of the Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratio in Patients with Recurrent Idiopathic Granulomatous Mastitis

Objective

The aim of this study was to investigate the relationship between the inflammatory parameters including neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) and the prognosis of idiopathic granulomatous mastitis (IGM).

Materials and methods

In this retrospective study, a total of 41 patients with IGM who had no malignant disease or inflammatory pathologies were included between January 2010 and December 2017. The patients were divided into two groups according to presence or absence of recurrence. Subsequently, the relationship between patient characteristics, pre- and postoperative NLR and PLR levels and disease recurrence were evaluated.

Results

With a mean follow-up period of 28.4 months, 19.5% of patients were found to have recurrent IGM. Age, body mass index, patient characteristics such as oral contraceptive use, smoking status, and family history, surgical treatment and postoperative NLR, preoperative PLR, and postoperative PLR were not statistically significant between groups. However, only preoperative NLR was significantly associated with a recurrent IGM (p=0.024). Preoperative NLR predicted recurrence with a sensitivity of 62.5% and specificity of 84.8%.

Conclusion

These results demonstrated that a high level of NLR was predictive of poor outcome in patients with IGM.

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

BACKGROUND

Granulomatous mastitis (GM) is an inflammatory breast disease of unknown aetiology. It poses diagnostic and therapeutic challenges with myriad forms of clinical presentation, varying results to treatments and propensity to recur. This study aims to look at clinical and treatment factors that predispose to recurrence of GM.

METHODS

We performed a retrospective review of 113 patients in our unit with histologically proven GM from 2006 to 2016. Demographic, clinical, treatment and outcomes data were collected and analysed.

RESULTS

Eighty-nine patients were treated with antibiotics (78.8%), 79 (69.9%) with steroids and 23 (20.4%) patients underwent surgery. Twenty (17.7%) patients had recurrence. Patients who presented with inflammatory signs and symptoms had increased odds of having subsequent recurrence: skin changes (1.50), pain (2.00), fistula (4.39) and antibiotic treatment (6.65). Four patients (20%) with recurrence had positive bacterial cultures. All 4 grew Corynebacterium. Patients with Corynebacterium infection had a 2.64 times higher risk of recurrence. Surgery did not preclude recurrence. There was a 70% (7/10) penicillin resistance rate in our patients with positive cultures for Corynebacterium.

CONCLUSION

Initial presentation with inflammatory signs and symptoms may confer increased risk of recurrence, warranting closer monitoring. Corynebacterium infection may play a part as a causative factor and risk factor for recurrence. Non-penicillin antibiotics should be considered as first-line antibiotics for patients presenting with inflammatory changes. Further prospective studies with larger patient populations might reveal information on the aetiology of GM and result in the development of a more standardized and effective treatment regimen.

Imaging features of granulomatous mastitis in 36 patients with new sonographic signs

PURPOSE

Idiopathic granulomatous mastitis is a rare relapsing benign inflammatory breast disease with unknown etiology. Its clinical features and imaging signs may mimic inflammatory breast cancer or some other inflammatory breast disease. This may interfere with correct and timely diagnosis and thus impose an additional burden on the costs of diagnosis and therapy, as well as patient anxiety. We aimed to characterize the imaging findings of this disease and introduce two new imaging signs.

MATERIALS AND METHODS

This prospective study examined 36 patients with imaging and a clinical diagnosis of mastitis granulomatosis who were untreated and then confirmed by pathology. Demographic information, clinical data, imaging findings, and signs were recorded.

RESULTS

The age range of the patients was 22-60 years with an average of 36 years. Most of the patients (78%) were at reproductive age. None of the patients had a family history of granulomatous mastitis. Most patients with granulomatous mastitis (89%) lived in regions with low socioeconomic status. For most patients, sonography indicated a heterogeneous hypoechoic mass with irregular shape and ill-defined margin (26 cases; 72.2%). Focal asymmetry (36%) and obscured mass (36%) were the most common mammographic findings. Two signs of duct ectasia containing secretion and high-flow pseudocyst appearance were described.

CONCLUSION

Mammographic and ultrasound findings can highly suggest a diagnosis of granulomatous mastitis in an appropriate clinical context.

Diagnostic techniques and multidisciplinary approach in idiopathic granulomatous mastitis: a revision of the literature

Idiopathic granulomatous mastitis (IGM) is a chronic benign inflammatory disease of the breast that may mimic breast cancer. It is most common in parous young fertile women, although it can occur in nulliparous women and in men. IGM is an idiopathic disease due to the influence of some environmental factors in genetically predisposed subjects. Several pathogenic hypothesis have been proposed in the last years (autoimmune, hormonal, infective genesis). IGM presents as a painful palpable mass located in one of the two udders. The skin is usually normal but could present signs of inflammation with or without lymph nodes involvement. Ultrasonography, mammography, magnetic resonance can be diagnosed an IGM, but pathognomonic radiological signs has not yet reported in literature. Biopsy findings show granulomatous lesion centered on the breast lobule, as in granulomatous mastitis induced by tuberculosis or sarcoidosis. The aim of this review of literature is to verify the development of new advanced diagnostic techniques and multidisciplinary approach for this condition. In the last years innovative approaches have modified IGM diagnosis and therapy, avoiding surgery in most of cases, introducing a more conservative medical approach based on recent etiopathological hypothesis. (www.actabiomedica.it)

Granulomatous Mastitis: A Therapeutic and Diagnostic Challenge

Granulomatous mastitis (GM) is a rare benign inflammatory breast disease that affects mostly women of childbearing age with a history of breastfeeding. The etiopathogenesis is still unknown; however, inflammation as the result of a reaction to trauma, metabolic or hormonal processes, autoimmunity, and an infection with Corynebacterium kroppenstedtii have all been implicated. Clinical findings are pain, mass, hyperemia, and inflammation. Because the clinical presentation can mimic infectious mastitis or inflammatory carcinoma, the disease course is often protracted. The diagnosis is made by histopathology. Biopsies show a granulomatous formation in combination with a localized infiltration of multi-nucleated giant cells, epithelioid histiocytes, and plasma cells. Ultrasound, mammography, and magnetic resonance imaging are not specific; however, ultrasound and mammography should be done to exclude other pathologies. Due to the lack of data including randomized controlled studies, the management of GM is controversial. In Western industrialized countries, most authors use a therapy regimen starting with antibiotics and corticosteroids, followed by continuous steroid therapy and surgery in patients with persisting symptoms. More data are needed to define the best therapy. The role of immunotherapy has not yet been ascertained. The implementation of a registry to collect more information on this rare disease is highly recommended.

Role of Bacteriological Agents in Idiopathic Granulomatous Mastitis: Real or Not?

Objective

Granulomatous mastitis is a rare, benign, chronic inflammatory disease of the breast of unknown etiology. This study evaluated bacteriologic agents that might play a role in the etiology of granulomatous mastitis using a molecular method with a universal primer after isolating deoxyribonucleic acid (DNA) from pathology specimens from patients diagnosed with granulomatous mastitis.

Materials and Methods

Breast biopsy material in the pathology department obtained between July 2008 and June 2013 was analyzed. The history of the granulomatous mastitis patients was examined in detail and paraffin block sections of the biopsy material were used to determine the presence of bacteria with a universal DNA primer.

Results

This study examined 45 granulomatous mastitis patients who had been diagnosed using excisional, incisional, or core biopsies. We evaluated multiple bacterial taxa, but obtained no positive result using a nucleic-acid-based assay with a universal primer.

Conclusion

The etiology of idiopathic granulomatous mastitis remains unclear. Further studies with a large number of patients should aim to identify the causative agent.

Steroids administered after vacuum-assisted biopsy in the management of idiopathic granulomatous mastitis

AIMS

The aetiology and treatment options for idiopathic granulomatous mastitis (IGM) are controversial. The aim was to study the clinical and diagnostic features and discuss medical and surgical treatment for IGM in our patients.

METHODS

Sixty-five patients who met the histological criteria for IGM were retrospectively studied. The diagnosis of IGM was confirmed using Mammotome (an ultrasound-guided, vacuum-assisted biopsy system), core needle biopsy, quadrantectomy or segmental resection. Forty-five patients were treated with prednisolone (69.2%). Immunohistochemical (IHC) staining for immune-related antigens (CD3, CD4, CD8, CD79a, IgG, and IgM) was performed.

RESULTS

Ultrasonography (USG) was carried out in all patients. Among them, 61 were considered to have an inflammatory mass and 15 had accompanying liquefaction. In four patients, the findings mimicked breast carcinoma (6.2%). The IHC results showed CD3, CD4, CD8 and CD79a lymphocytes diffusely distributed in the lesion. Stains for IgG and IgM were negative. Prednisolone was administered to the patients diagnosed with IGM. The success rate was 53 (81.5%) and the whole recurrence was 12 (18.5%). The median follow-up period was 12 months (range 4-42 months).

CONCLUSIONS

The aetiology of IGM remains uncertain. The disease has no propensity for the right or left breast. It is a local autoimmune disease, involving humoral and cell-mediated immunity. Hyperprolactinaemia may play a role in some patients. Corticosteroids administered after complete removal of the IGM lesion using the Mammotome biopsy system is an effective treatment option.

Clinical metagenomic analysis of bacterial communities in breast abscesses of granulomatous mastitis

BACKGROUND

Granulomatous mastitis (GM) is a chronic inflammatory breast lesion. Its etiology remains incompletely defined. Although mounting evidence suggests the involvement of Corynebacterium in GM, there has been no systematic study of GM bacteriology using -omics technology.

METHODS

The bacterial diversity and relative abundances in breast abscesses from 19 women with GM were investigated using 16S rDNA metagenomic sequencing and Sanger sequencing. A quantitative PCR (qPCR) assay was also developed to identify Corynebacterium kroppenstedtii.

RESULTS

A bioinformatic analysis revealed that Corynebacterium was present in the 19 GM patients, with abundances ranging from 1.1% to 58.9%. Of note, Corynebacterium was the most abundant taxon in seven patients (more than a third of the subjects). The predominance of Corynebacterium kroppenstedtii infection (11 of 19 patients, 57.9%) was confirmed with Sanger sequencing and the qPCR assay.

CONCLUSIONS

This study profiled the microbiota of patients with GM and indicated an important role for Corynebacterium, and in particular C. kroppenstedtii, in the pathogenesis of this disease.

Granulomatous Mastitis: A Rare Cause of Male Breast Lump

Background

Mastitis is a common benign disorder of the female breast. It is frequently associated with tenderness, swelling and nipple discharge. We are describing an extremely rare case of an idiopathic granulomatous mastitis in the male breast. Only 1 previous case was reported.

Case Report

A 29-year-old male patient presented with a hard, painless lump in the right breast of 2 weeks duration. The patient underwent surgical excision with margin. The histopathologic findings were consistent with granulomatous mastitis. The case was reported as idiopathic granulomatous mastitis after exclusion of all known causes of the disease.

Conclusion

Granulomatous mastitis is rare in females and extremely rare in male breast tissue. Since this disease mimics breast cancer in its clinical picture and radiologic findings are usually not conclusive, surgical excision is recommended in all cases.

Granulomatous lobular mastitis

Granulomatous lobular mastitis is an unusual breast benign inflammatory disorder with unknown aetiology. It is generally emerged with the clinical symptoms of breast mass, abscess, inflammation and mammary duct fistula. The diagnosis is made by histopathology with a chronic non-necrotizing granulomatous inflammation in lobules of the breast tissue as the microscopic feature. Therapy of granulomatous lobular mastitis consists of surgical, medication treatment or combination of both, but now researches suggest that observational management is an acceptable treatment.

Idiopathic granulomatous mastitis: presentation, investigation and management

Idiopathic granulomatous mastitis (IGM) is a rare chronic inflammatory condition of the breast which although benign can mimic carcinoma. Establishing a diagnosis can be challenging and requires a high index of suspicion with exclusion of infective and autoimmune breast diseases. IGM is characterized histologically by noncaseating granulomas which are of a lobulo-centric pattern and often associated with microabscess formation. Management of confirmed cases remains controversial with proponents of initial surgical or medical therapies - each has its associated problems which can be worse than the original symptoms of IGM. However, many patients require more than one modality of treatment to completely resolve IGM lesions and careful judgment is necessary to ensure optimal type and sequencing of treatments.