Aetiology of idiopathic granulomatous mastitis

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.

Imiquimod as a new treatment in refractory idiopathic granulomatous mastitis: report of two cases

INTRODUCTION

Idiopathic granulomatous mastitis (IGM) is a rare chronic inflammatory lesion of the breast that mimics breast cancer or infection. Immunological pathogenesis is strongly suggested for the disease.

REASON FOR THE REPORT

The treatment remains controversial, comprising a spectrum from observation or NSAIDs to immunosuppressive agents and surgery. Intractable cases are not uncommon and represent a major treatment challenge. Therefore in this study, we examine the effect of a topical immunomodulator agent, imiquimod, on refractory IGM. Patient 1 had IGM for 9 months and had not responded to the existing treatments. She responded to a 7-week course of imiquimod. In patient 2, the disease had begun 4 months sooner and had been resistant to all treatments; it responded to imiquimod after 4 weeks. Ulcers appeared on the skin of both patients but resolved safely.

OUTCOME

Both patients were very satisfied with the results. Imiquimod can be an appropriate local treatment with limited adverse effects in refractory IGM. We propose similar studies to assess the efficacy of imiquimod in IGM further, paying attention to the possibility of developing skin wounds.

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).

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Invasive Breast Cancer of No Special Type With Osteoclast-Like Giant Cells: A Cytological Clue Providing the Final Diagnosis for Histology

Breast cancer associated with osteoclast-like giant cells (OGCs) refers to a morphological pattern of invasive breast carcinoma of non-special type. Their presence is sometimes subtle, but OGCs can be appreciated both histologically and immunohistochemically. The origin of OGCs as well as their implication for prognosis remain debated. We describe the case of a 65-year-old woman, wherein the presence of OGCs in the fine-needle aspiration cytology of a metastatic axillary lymph node suggested the final diagnosis on histology. The differential diagnosis is broad, and here we provide evidence for strict cytological-histological correlation when dealing with unusual breast lesions.

Granulomatous mastitis in accessory breast tissue: A rare presentation and surgical management

Granulomatous mastitis (GM) in accessory breast tissue is rare. The present study aimed to report a rare case of GM in accessory breast tissue. A 39-year-old female patient presented with right axillary discomfort and swelling for ~5 days. On clinical examination, a tender, firm lump was detected in the right axillary region. The ultrasound showed diffuse parenchymal heterogeneity and surrounding edema in the right accessory breast associated with reactive axillary lymph nodes. Following unresponsiveness to conservative treatment, a surgical procedure was performed in the form of an excisional biopsy and the lesion was diagnosed as GM. During the six-month follow-up, there were no recurrences. The exact cause of GM remains uncertain and the etiology within accessory breast tissue is even less understood. Proposed mechanisms suggest that it may result from an exaggerated immune response triggered by various factors, such as infection, autoimmunity or hormonal fluctuations. GM in accessory breast tissue is a rare and challenging clinical condition to be diagnosed. Due to the rarity of this condition, it highlights the importance of including GM in the differential diagnosis of axillary masses.

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.

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.

Clinical Characteristics of Idiopathic Granulomatous Mastitis in a Hispanic Border Population: A Case Series and Literature Review

Idiopathic granulomatous mastitis (IGM) is an autoimmune condition of the breast that is commonly encountered in women of non-white ethnicity such as Southeast Asians, Middle Easterners, and Hispanics. This condition often presents as a painful breast mass, and many patients undergo invasive diagnostic procedures or surgical excision, which can lead to disfiguring scars. Early recognition and prompt treatment with immunosuppressive medications can prevent invasive workups and management. Although previously thought to require an exclusively surgical approach, it now prompts interdisciplinary management. In this context, we present a case series of patients with IGM in a Hispanic population of South Texas.

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.

Idiopathic Granulomatous Mastitis

Idiopathic granulomatous mastitis (IGM) is a rare, benign inflammatory disorder of the breast that is often underrecognized. The exact etiology and pathophysiology are unknown, but milk stasis is felt to play a role. Classically, this condition is noninfectious, but many cases are noted to be associated with Corynebacterium species. Most patients affected are parous women with a mean age of 35, and many have breastfed within five years of diagnosis. Patients typically present with a painful mass and symptoms of inflammation, and these features can sometimes mimic breast cancer. Biopsy is needed to make a definitive diagnosis, and noncaseating granulomas are found on core biopsy. Many patients have a waxing and waning course over a period of six months to two years. Goal of treatment is to avoid surgery given poor wound healing, high risk of recurrence, and poor cosmetic outcomes. Medical treatment is preferred and includes observation, antibiotics, steroids, and immune modulators such as methotrexate. In more recent years, topical and intralesional steroids have become the treatment of choice, with similar outcomes to oral steroids.

Granulomatous mastitis in a 50-year-old male: A case report and review of literature

BACKGROUND

Granulomatous mastitis (GM) an inflammatory disease of the breast that usually affects women of childbearing age, occurs very rarely in males.

CASE SUMMARY

We present a case study of a 50-year-old male patient with GM. The patient developed a breast lump following the cleaning of a previously embedded dirt-filled nipple. While an initial improvement was noted with antibiotic therapy, a recurrence occurred a year later, showing resistance to the previously effective antibiotics. Subsequently, the lesion was excised. The histopathological examination confirmed the diagnosis of GM.

CONCLUSION

GM should be considered a possible diagnosis of male breast masses.

A hematological parameter-based model for distinguishing non-puerperal mastitis from invasive ductal carcinoma

Purpose

Non-puerperal mastitis (NPM) accounts for approximately 4-5% of all benign breast lesions. Ultrasound is the preferred method for screening breast diseases; however, similarities in imaging results can make it challenging to distinguish NPM from invasive ductal carcinoma (IDC). Our objective was to identify convenient and objective hematological markers to distinguish NPM from IDC.

Methods

We recruited 89 patients with NPM, 88 with IDC, and 86 with fibroadenoma (FA), and compared their laboratory data at the time of admission. LASSO regression, univariate logistic regression, and multivariate logistic regression were used to screen the parameters for construction of diagnostic models. Receiver operating characteristic curves, calibration curves, and decision curves were constructed to evaluate the accuracy of this model.

Results

We found significant differences in routine laboratory data between patients with NPM and IDC, and these indicators were candidate biomarkers for distinguishing between the two diseases. Additionally, we evaluated the ability of some classic hematological markers reported in previous studies to differentiate between NPM and IDC, and the results showed that these indicators are not ideal biomarkers. Furthermore, through rigorous LASSO and logistic regression, we selected age, white blood cell count, and thrombin time to construct a differential diagnostic model that exhibited a high level of discrimination, with an area under the curve of 0.912 in the training set and with 0.851 in the validation set. Furthermore, using the same selection method, we constructed a differential diagnostic model for NPM and FA, which also demonstrated good performance with an area under the curve of 0.862 in the training set and with 0.854 in the validation set. Both of these two models achieved AUCs higher than the AUCs of models built using machine learning methods such as random forest, decision tree, and SVM in both the training and validation sets.

Conclusion

Certain laboratory parameters on admission differed significantly between the NPM and IDC groups, and the constructed model was designated as a differential diagnostic marker. Our analysis showed that it has acceptable efficiency in distinguishing NPM from IDC and may be employed as an auxiliary diagnostic tool.

Idiopathic granulomatous mastitis with extramammary manifestations: a case report

Introduction and Importance

Granulomatous mastitis is a rare inflammatory disorder of the breast, which can be either idiopathic or due to secondary etiology. This disease affects women of reproductive age. The exact pathophysiology underlying idiopathic granulomatous mastitis (IGM) remains unclear, but it is believed to be mediated by immunological processes. Establishing a diagnosis of this condition could be challenging due to the long list of differential diagnoses that it creates.

Case Presentation

We report a 24-year-old Syrian female presented to the clinic complaining of a 2-week history of fatigue, fever and chills, swelling, and localized pain in her left breast. Physical examination revealed erythema nodosum, episcleritis, and arthralgia in the wrists, ankles, and elbows. An excisional biopsy was done and a microscopic examination of the lesion confirmed granulomatous perilobular mastitis. Symptoms had resolved after the surgical excision and follow-up evaluation showed no signs of recurrence.

Clinical Discussion

IGM typically presents as an enlarging breast mass that can be mistaken for breast cancer or an abscess. The diagnostic approach should consider the presence of extramammary symptoms such as fever, arthralgia, and fatigue. Treatment options include corticosteroids, surgical excision, or steroid-sparing agents, but relapse rates vary.

Conclusions

Episcleritis should be considered as a potential extramammary manifestation in cases of IGM. We highlight the importance of recognizing and investigating the potential systemic involvement in patients with IGM. Accurate interpretation of pathological and radiological findings by a multidisciplinary breast team can facilitate the diagnosis and reduce unnecessary interventions.

Clinical, histological features, and predictors of relapse in patients with idiopathic granulomatous mastitis

Idiopathic granulomatous mastitis is a benign, inflammatory disease of breasts characterized by non-caseating granulomas. Our study aims to identify distinguishing clinical and histopathological features of relapsing disease compared to those in complete remission. We queried databases at our institution (1990-2021) to include females ≥18 years with biopsy-proven diagnosis of idiopathic granulomatous mastitis, excluding patients with breast cancer, lymphoproliferative disorders, solid organ malignancy, foreign body reaction in breast, plasma cell mastitis, and ductal ectasia. Remission was defined as a 3-month period without recurrence of symptoms or imaging findings. Relapse was defined as recurrence after 3 months of remission. Clinical and histopathological features were compared using 2-sample t tests and chi-squared tests. Of the 27 patients that met our inclusion criteria, the mean age at diagnosis was 35.8 years (± standard deviation 9.4 years) with a mean body mass index of 31.7 kg/m2 (± standard deviation 6.7 kg/m2). 11 (41%) were Hispanic, 25 (93%) had at least one previous full-term pregnancy prior to diagnosis and 8 (30%) were on oral contraceptives. Remission was seen in 18 patients (66%) and 9 (33%) had relapse. Six of these patients received steroids after antibiotics, while 5 patients received methotrexate. Three (33%) patients with relapse and 14 (77%) with remission, had abscess formation confirmed on histopathology (P = .04). Patients with remission had a higher number of abscesses on histopathology and history of oral contraceptive use was associated with more relapse. By identifying key clinical and histopathological findings in this population may guide prognosis and treatment of these patients.

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

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

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.

Cystic neutrophilic granulomatous mastitis: A case report and review of the literature

The present study describes a case of cystic neutrophilic granulomatous mastitis. The clinical and radiological findings of the patient were consistent with idiopathic granulomatous mastitis. Cystic neutrophilic granulomatous mastitis is a rare subtype of mastitis with a distinct histological pattern that is associated with the Corynebacterium species. The diagnosis and treatment of cystic neutrophilic granulomatous mastitis remains a significant challenge due to the scarcity of available data. The present study describes a classic case of cystic neutrophilic granulomatous mastitis that includes clinical, radiological and histopathological findings. To the best of our knowledge, this is the first case documenting radiological findings before and after treatment. This report encourages the consideration of this entity in the differential diagnoses of mastitis.

What predicts the recurrence in ıdiopathic granulomatous mastitis?

INTRODUCTION

Idiopathic granulomatous mastitis (IGM) is a rarely seen chronic and benign disease of the breast. IGM usually emerges in women between 30 and 45 years of age and within the first 5 years after lactation. There is no consensus on the treatment of the disease. Steroids, immunosuppressive agents such as methotrexate and azathioprine, antibiotics, and surgical and conservative treatments can be preferred. In the present study, it was aimed to demonstrate the treatment options and follow-up data of the patients with IGM and to investigate the effective factors on recurrence if developed in the follow-up period.

MATERIALS AND METHOD

The data of 120 patients diagnosed with idiopathic granulomatous mastitis were evaluated for this cross-sectional retrospective study. The demographic, clinical, treatment, and follow-up features of the patients were obtained from the file records.

RESULTS

The median age value of the 120 female patients included in the study was 35 (24-67) years. Of the patients, 45%, 79.2%, 49.2%, and 15% had a past history of surgical intervention, steroid use, methotrexate use, and azathioprine use, respectively. Recurrent lesion developed after the treatment in 57 (47.5%) patients. The recurrence rate was 66.1% in the patients who underwent surgical intervention in the initial treatment. There was a statistically significant difference between the patients with and without recurrence regarding the presence of abscess, the presence of recurrent abscess, and having surgical intervention as the initial treatment in the past history. The rate of having surgery was statistically significantly higher compared with the administration of steroid therapy alone and the combination of steroid and immunosuppressive therapy in the initial treatment of the patients who developed recurrence. The rate of having surgery together with the administration of steroid and immunosuppressive therapy was statistically significantly higher than the administration of steroid and immunosuppressive therapies.

DISCUSSION

Our study showed that surgical intervention and the presence of abscess increased recurrence in the treatment of IGM. Key Points • This study has shown that surgical intervention and the presence of abscess increase recurrence. • A multidisciplinary approach to the treatment of IGM and management of the disease by the rheumatologists may be critical.

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

Background

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

Patients and methods

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

Results

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

Conclusion

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Granulomatous Mastitis With Breast Abscess Caused by Salmonella

Granulomatous mastitis (GM) is a rare disease that occurs in young premenopausal women, is mostly idiopathic, and is less likely to be caused by infection and trauma. It is also strongly associated with pregnancy, lactation, and hyperprolactinemia. GM superimposed by infection with abscess formation caused by Salmonella is extremely rare. Upon reviewing the literature, our case is considered to be the first reported case globally. Most breast abscesses are caused by Staphylococcus aureus.

Idiopathic Granulomatous Mastitis (IGM): Clinical Features and Non-Surgical Management

Background: Idiopathic Granulomatous Mastitis (IGM) is a benign disease; it can clinically and radiologically mimic the symptoms of breast cancer. Objectives: Due to the rare and limited number of studies in Iran, this study was designed and conducted to evaluate patients' clinical characteristics and treatment management with IGM. Methods: In this cross-sectional and retrospective descriptive-analytic study, we studied the medical records of 293 patients with IGM, such as demographic information, characteristics of breast lesions, type of treatment, complications, and their outcome, which were recorded in the Cancer Research Centers of Shahid Beheshti University of Medical Sciences (SBMU) from 2010 to 2019. The patients were contacted by telephone to visit clinically or collect additional information. Data were analyzed by SPSS software version 24. Results: The mean age of patients was 39.21 (ST = 8.29) years. Breast involvement in 236 cases (80.5%) was unilateral, and in 50 cases (17.1%), the involvement was Pere pri-Areola. The most common type of treatment was conservative therapy (analgesia + drainage) (178 cases, 60.8%), which was the primary treatment in our study; 66 patients (22.5%) received antibiotic therapy + analgesia + drainage, and 41(14%) cases received corticosteroid in addition to this treatment. Totally, 132 cases (79.5%) were completely cured with the performed treatments, 17 cases (5.8%) had a recurrence of symptoms, and 14.7% of the patients were still receiving treatment. Recurrence after 1 year in patients who had a longer duration of disease (more than 12 months) was higher than in those who had a shorter period (less than 12 months) (15.3% vs. 5.1%, P = 0.004). Also, the highest recurrence rate was in the group receiving corticosteroids compared to the group receiving the usual treatment and usual treatment plus antibiotics. This relationship was statistically significant (22.0% vs. 9 % and 6.1%, respectively, P = 0.032). Complications (scar or breast skin color change) were significantly higher in patients without a pregnancy history than in patients who had pregnancy (50.0% vs. 22.8%, P = 0.030). Also, these complications were significantly higher in patients who had a longer duration of disease (more than 12 months) than in shorter periods of disease (less than 12 months) (31.4% vs. 17.3%, P = 0.005). Conclusions: The results of our study and its comparison with the results of other studies still emphasize the uncertainty of the etiology of IGM disease and its treatment, but to some extent, our study has shown that conservative treatment (drainage with analgesic drugs) is one of the best treatment options. Also, corticosteroid therapy is associated with a higher recurrence rate, but in some cases is necessary and recommended in many studies.

Shear Wave Elastography-Correlated Dose Modifying: Can We Reduce Corticosteroid Doses in Idiopathic Granulomatous Mastitis Treatment? Preliminary Results

Idiopathic granulomatous mastitis (IGM) is a chronic inflammatory breast disease treated with local and systemic corticosteroids. This study aims to evaluate the efficacy of reducing corticosteroids doses in IGM cases based on shear wave elastography (SWE) tissue stiffness measurements. This prospective study included IGM patients who received systemic or local corticosteroids between January 2020 and September 2022. A 20% or more reduction in tissue elasticity values (kPa) was considered a positive response to treatment in the study group, and the corticosteroids dose was reduced. The control group was dosed routinely. All patients were followed for 2 years to compare treatment efficacy, duration, total corticosteroids dose, recurrence, and side effects. There were 12 patients (9 local/3 systemic corticosteroids) in the study group and 24 patients (17 local/7 systemic corticosteroids) in the control group. Ten (83.4%) out of 12 patients in the study group were successfully treated by reducing corticosteroid doses with follow-up, and 2 (16.6%) out of 12 patients were reverted to the initial treatment protocol due to an increase in elasticity values during the follow-up. Nevertheless, successful treatment results were obtained in these two patients without reducing the corticosteroid dose. When compared to the control group, the median corticosteroid dose in the study group was significantly lower in patients using both local (p < 0.01) and systemic (p < 0.01) corticosteroids. A significant negative correlation was found between the rate of decrease in elasticity values and the median dose of corticosteroids (r = −0.649, p < 0.05) and the median treatment time (r = −0.751, p < 0.01). Side effects due to corticosteroids were found to be significantly lower in the study group (p < 0.05). According to our first and preliminary results, the SWE-correlated dose-modifying technique may reduce corticosteroid doses and side effects without significantly compromising treatment efficacy.

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.

Identification of periductal mastitis and granulomatous lobular mastitis: a literature review

Background and Objective

Non-puerperal mastitis (NPM) is a breast disease with poor clinical manifestations, which seriously affects women's health and quality of life. Due to the low incidence rate of the disease and the paucity of related research, there is much misdiagnosis and mis-management of periductal mastitis (PDM) and granulomatous lobular mastitis (GLM). Therefore, understanding the differences between PDM and GLM, in terms of etiology and clinical manifestations, is crucial for patient treatment and prognosis. At the same time, choosing different treatment methods may not achieve the best treatment effect, so the appropriate treatment method can often reduce the patient's pain and reduce the recurrence of the patient's disease.

Methods

The PubMed database was searched for articles published from 1 January 1990 to 16 June 2022 using the following search terms: "non-puerperal mastitis", "periductal mastitis", "granulomatous lobular mastitis", "mammary duct ectasia", "idiopathic granulomatous mastitis", "plasma cell mastitis", and "identification". The key findings of the related literatures were analyzed and summarized.

Key Content and Findings

We systematically described the key points in the differential diagnosis, treatment, and prognosis of PDM and GLM. The use of different animal models for research and novel drugs to treat the disease were also described in this paper.

Conclusions

The key points in the differentiation of the two diseases are clearly explained, and the respective treatment options and prognosis are summarized.

Idiopathic Granulomatous Mastitis: Six years of experience and the current evidence in literature

Objectives

This study aimed to retrospectively describe the clinicopathological pattern and management experience of idiopathic granulomatous mastitis in women receiving care at the Royal Hospital, a tertiary care centre in Oman. The study then compared the researchers' experience with the current literature trends.

Methods

The data of patients from January 2012 to December 2017 were reviewed retrospectively, after receiving ethical approval from the Centre of Studies and Research.

Results

This retrospective study included 64 patients were confirmed to have idiopathic granulomatous mastitis. All patients were in the premenopausal phase, with only one being nulliparous. Mastitis was the most common clinical diagnosis; furthermore, half of the patients had a palpable mass. Most patients had received antibiotics during the span of their treatment. Drainage procedure was done in 73% of the patients, whereas excisional procedure was done for 38.7%. Only 52.4% of patients were able to achieve complete clinical resolution within six months of follow-up.

Conclusion

There is no standardised management algorithm due to the paucity of high-level evidence comparing different modalities. However, steroids, methotrexate and surgery are all considered to be effective and acceptable treatments. Moreover, current literature tends towards multimodality treatments planned tailored case-to-case based on the clinical context and patients' preference.

Profiling Microbial Communities in Idiopathic Granulomatous Mastitis

Idiopathic granulomatous mastitis (IGM) is a rare and benign inflammatory breast disease with ambiguous aetiology. Contrastingly, lactational mastitis (LM) is commonly diagnosed in breastfeeding women. To investigate IGM aetiology, we profiled the microbial flora of pus and skin in patients with IGM and LM. A total of 26 patients with IGM and 6 patients with LM were included in the study. The 16S rRNA sequencing libraries were constructed from 16S rRNA gene amplified from total DNA extracted from pus and skin swabs in patients with IGM and LM controls. Constructed libraries were multiplexed and paired-end sequenced on HiSeq4000. Metagenomic analysis was conducted using modified microbiome abundance analysis suite customised R-resource for paired pus and skin samples. Microbiome multivariable association analyses were performed using linear models. A total of 21 IGM and 3 LM paired pus and skin samples underwent metagenomic analysis. Bray−Curtis ecological dissimilarity distance showed dissimilarity across four sample types (IGM pus, IGM skin, LM pus, and LM skin; PERMANOVA, p < 0.001). No characteristic dominant genus was observed across the IGM samples. The IGM pus samples were more diverse than corresponding IGM skin samples (Shannon and Simpson index; Wilcoxon paired signed-rank tests, p = 0.022 and p = 0.07). Corynebacterium kroppenstedtii, reportedly associated with IGM in the literature, was higher in IGM pus samples than paired skin samples (Wilcoxon, p = 0.022). Three other species and nineteen genera were statistically significant in paired IGM pus−skin comparison after antibiotic treatment adjustment and multiple comparisons correction. Microbial profiles are unique between patients with IGM and LM. Inter-patient variability and polymicrobial IGM pus samples cannot implicate specific genus or species as an infectious cause for IGM.

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?

Mammography and Digital Breast Tomosynthesis in Granulomatous and Nongranulomatous Mastitis

INTRODUCTION

Digital Mammography (DM) is extensively used for breast imaging however, lesion visibility is often limited by overlapping tissues, which affects lesion characterization. Digital breast tomosynthesis (DBT) reduces the effect of overlapping tissues and helps in revealing obscured findings. We aimed to describe the mammographic findings in granulomatous and non-granulomatous mastitis and assess the utility of adjunctive DBT in lesion characterization.

MATERIALS AND METHODS

DM and DBT images of histo-pathologically diagnosed cases of granulomatous (GM) and non-granulomatous mastitis (NGM) were reviewed according to the BI-RADS lexicon. Presence of contiguous/ interconnected lesions, tubular densities, interspersed hypodensities/fat densities within the involved areas were also assessed. The perceived utility of adjunct DBT was scored from 0-2.

RESULTS

Of 33 reviewed patients (24 GM, 9 NGM; median age 39 years, range 24-78); 13/33 (39.4%) were under 35 years of age. DBT detected masses in 24/33 (72.7%), whereas only 15/33 (45.4%) were visible on DM alone. Contiguous or inter-connected lesions were found in 10/33 (30.3%) cases. Tubular extensions were seen in 14 cases and interspersed hypodensities in 15. None of the enlarged lymph nodes had irregular shape or indistinct margins or loss of fatty hilum. DBT was able to categorize more lesions as BIRADS 4a or below, as compared to DM alone.

CONCLUSIONS

Mammographic presence of multiple contiguous iso-dense masses, reniform contour of axillary lymph nodes with preserved fatty hilum despite a large area of breast involvement favour a benign etiology; especially if DBT reveals tubular extensions or lesions with inhomogenous low density areas within.

Biomedical Indicators of Patients with Non-Puerperal Mastitis: A Retrospective Study

BACKGROUND

Non-puerperal mastitis (NPM), a recurrent chronic inflammation of non-lactating breast, often proves tremendous difficulty in treatment, and it may give rise to its complicated symptoms and unclear etiology. Furthermore, the clinical morbidity rate of NPM has been increasing in recent years.

METHODS

Overall, 284 patients diagnosed with NPM were consecutively recruited as cases in this study, and patients with benign breast disease (n = 1128) were enrolled as control. The clinical, biomedical, and pathological indicators were analyzed. Univariate and multivariate logistic analysis were used to distinguish risks between NPM and benign breast mass patients. Furthermore, according to the pathological characteristics, the patients of NPM were classified into two subgroups: mammary duct ectasia (MDE) and granulomatous lobular mastitis (GLM). The differences of biomedical indicators between MDE and GLM groups were also analyzed.

RESULTS

Compared with benign breast mass group, the level of high-density lipoprotein (HDL-C) significantly decreased, while lipoprotein(a) (Lp(a)) and blood glucose (GLU) both increased in NPM group. According to univariate and multivariate logistic analysis, the onset age and HDL-C were generally decreased, while Lp(a) and GLU were increased in NPM group. The onset age, HDL-C, Lp(a), and GLU were modeled to distinguish NPM and benign breast mass. Significant differences were also observed between MDE and GLM patients in biomedical indicators, such as lipoprotein(a) (Lp(a)), lactate dehydrogenase (LDH), creatine kinase (CK), total cholesterol (TC), and so on.

CONCLUSIONS

Our results indicated for the first time that biomarkers were associated with NPM. The biomedical indicators involved in lipid metabolism might be important factors in the development and treatment of NPM. In addition, MDE and GLM are two diseases with different inflammatory states of NPM. These findings would be helpful for a better understanding of NPM and give us some insights to develop new diagnostic and therapeutic strategies.

Lactation mastitis: Promising alternative indicators for early diagnosis

Although lactation mastitis (LM) has been extensively researched, the incidence rate of LM remains a salient clinical problem. To reduce this incidence rate and achieve a better prognosis, early and specific quantitative indicators are particularly important. It has been found that milk electrolyte concentrations (chloride, potassium, and sodium) and electrical conductivity (EC) significantly change in the early stages of LM in an animal model. Several studies have evaluated EC for the detection of subclinical mastitis in cows. EC, chloride, and sodium content of milk were more accurate for predicting infection status than were other variables. In the early stages of LM, lactic sodium, chloride, and EC increase, but potassium decreases. However, these indicators have not been reported in the diagnosis of LM in humans. This review summarizes the pathogenesis and the mechanism of LM in terms of milk electrolyte concentration and EC, and aim to provide new ideas for the detection of sub-clinical mastitis in humans.

Tissue proteome analysis revealed an association between cancer, immune system response, and the idiopathic granulomatous mastitis

Idiopathic Granulomatous Mastitis (IGM) is a disease that clinically mimics breast cancers with symptoms of pain, edema, erythema, nipple discharge, nipple retraction, and fistula. Although IGM is considered to be formed by autoimmune responses or infections, the molecular mechanism behind formation and progress is unknown. Therefore, in this study, we aimed to investigate molecular mechanisms underlying IGM formation, progress, and recurrence by monitoring the changes at the proteome level. Protein extracts prepared from IGM (n = 15) and within-control tissues (n = 15) were subjected to nHPLC followed by LC-MS/MS proteomic analysis. Label-free quantitation analysis revealed that sixty differentially regulated between the two groups. Those proteins were classified based on their role in metabolic pathways using bioinformatics tools. Based on DAVID analysis, 16 of the differently regulated proteins were associated with the immune system, while 17 proteins were involved in cancer metabolism. STRING analysis showed that five of the differentially regulated proteins were associated with combined immune deficiency which were PNP, TAP1, ITGAL, PRKDC, and PTPRC while the other proteins were involved in insulin response and neutrophil degranulation. This study is one of the very few studies that investigated the changes in protein expressions of IGM tissues compared to controls. For the first time, we have shown the relationship of IGM with the immune system at the protein level and also underlined the cancer-like behavior of the disease. Furthermore, the proteins that were pointed out as combined immune deficiency-related proteins may have value as diagnostic markers for idiopathic granulomatous mastitis although further studies are needed to shed more light on the pathogenesis of the disease.

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.

Idiopathic granulomatous mastitis: experience at a New York hospital

INTRODUCTION

Idiopathic granulomatous mastitis (IGM) often mimics breast cancer. Presentation includes pain, palpable mass, suppuration or suspicious imaging. Widely reported in Asia and the Middle East, IGM is diagnosed after excluding specific granulomatous mastitis (SGM). Aetiology remains unknown. Lactation, prolactinaemia, ethnicity, autoimmune disease and Corynebacteria are associated. Treatment is controversial and the prevalence rising. Surgery and non-operative treatments including antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), steroids, methotrexate and observation have advocates.

METHODS

A retrospective chart review of 63 patients with IGM from 2008 to 2018 was undertaken focusing on birthplace, age, clinical presentation, wound cultures, imaging, treatments and outcomes.

RESULTS

Sixty-one of 63 patients were Hispanic; 53 were Mexican-born women aged 23-46. Clinical presentation included pain, painful mass, painless mass, suppuration and abnormal imaging. Some 31/61 ultrasound examinations and 17/33 mammograms were deemed Breast Imaging Reporting and Data System (BI-RADS) score 4 or 5. Management included antibiotics (43), incision and drainage (24), NSAIDs (29), steroids (8), lumpectomy (18) and observation (12). Some 12/20 patients with painless masses resolved with observation, 3 received NSAIDs, 2 received steroids and 3 underwent lumpectomies. Antibiotics resolved 8/43 cases, 5 needed incision and drainage, 26 received NSAIDs, 6 received steroids and 5 underwent lumpectomies. Nineteen patients had indolent disease or recurrence.

CONCLUSIONS

Excluding malignancy is critical, treatment challenging and recurrence common in IGM. A preponderance of patients were Mexican-born, similar to other reports from the USA. Over 50% of IGM cases had suspicious BI-RADS scores. Best management remains a challenge and ranges from observation to lumpectomy.

Comparison of the Efficacy of Systemic Versus Local Steroid Treatment in Idiopathic Granulomatous Mastitis: A Cohort Study

INTRODUCTION

Steroid therapy is known to be effective against granulomatous mastitis. We aimed to compare the efficacy of local versus systemic steroid administration in patients with idiopathic granulomatous mastitis.

MATERIALS AND METHODS

This prospective cohort study included 58 patients who had either local (n = 42) or systemic (n = 16) treatment due to granulomatous mastitis between 2015 and 2019. Recurrence rates were determined as per ultrasound and magnetic resonance imaging examinations and the rate of side effects was evaluated as per patient complaints and physical examinations at the end of a 2-year follow-up period.

RESULTS

Median doses of 140 mg and 3810 mg were administered to the local and systemic group, respectively. Six (14.3%) patients in the local treatment group and 13 (81.3%) in the systemic treatment group had steroid-related side effects. The local treatment group had significantly fewer side effects than the systemic treatment group (P < 0.001). The recurrence rates were similar in both groups (P > 0.05).

CONCLUSIONS

Local steroid injection was as effective as systemic steroid therapy. Compared to systemic therapy, local steroid administration can be considered as a new therapeutic protocol with a lower dose and side effect rate.

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.

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.

Interactions between the breast tissue microbiota and host gene regulation in nonpuerperal mastitis

BACKGROUND

Nonpuerperal mastitis (NPM) causes considerable psychological distress in females, since it is difficult to diagnose and treat. A spectrum of etiological factors can lead to NPM. However, the pathogenesis of NPM remains unclear. Here, we aimed to dissect the role of host gene-microbe interactions in NPM.

METHODS

We compared the breast tissue microbiome between NPM patients and controls using 16S rRNA sequencing. We also compared the gut microbiome between NPM patients and healthy controls. Moreover, we investigated whether the breast tissue microbiome was associated with an altered gut microbiome in patients with NPM. We analyzed differentially expressed genes in inflammatory tissues of mammary gland from patients with NPM and normal mammary gland tissues from patients with benign and non-infectious breast disease by RNA-sequencing (RNA-seq). Lastly, we explored the association of specific bacterial taxa with differential expression of immune-related genes and differences in infiltrating immune cells.

RESULTS

The breast tissue microbiome from NPM and controls showed significant differences in community composition. The breast tissue shared a relatively small proportion of bacterial communities with the gut in patients with NPM. Ruminococcus (family Ruminococcaceae) of breast tissue was positively correlated with the differentially expression of immune-related genes between NPM patients and controls, including antigen processing and presentation genes (ICAM1, LGMN, THBS1, TAP1, HSPA1B and HSPA1A), cytokine receptor gene IL15RA, and chemokine gene CCN1. Rhizobium of breast tissue was negatively correlated with the differentially expression of the antigen processing and presentation gene HSPA6 between NPM patients and controls. We also found that Ruminococcus (family Ruminococcaceae), Coprococcus, and Clostridium of breast tissue positively correlated with the difference of CD8⁺ T cells between NPM patients and controls.

CONCLUSIONS

We preliminarily explored the potential role of host-microbe interactions in NPM. We demonstrate cross-talk between the breast tissue microbiome and the gut microbiome in patients with NPM. We suggest that NPM microbiome composition influences the immune microenvironment of the disease by affecting the transcriptome. This is an exploratory study and further investigation of host-microbe interactions and its potential mechanism in NPM development are warranted.