Treatment of Granulomatous Mastitis: Is There a Role for Antibiotics?

Corynebacterium parakroppenstedtii secretes a novel glycolipid to promote the development of granulomatous lobular mastitis

Granulomatous lobular mastitis (GLM) is a chronic idiopathic granulomatous mastitis of the mammary gland characterized by significant pain and a high propensity for recurrence, the incidence rate has gradually increased, and has become a serious breast disease that should not be ignored. GLM is highly suspected relative to microbial infections, especially those of Corynebacterium species; however, the mechanisms involved are unclear, and prevention and treatment are difficult. In this study, we demonstrated the pathogenicity of Corynebacterium parakroppenstedtii in GLM using Koch's postulates. Based on the drug sensitization results of C. parakroppenstedtii, and utilizing a retrospective study in conjunction with a comprehensive literature review, we suggested an efficacious, targeted antibiotic treatment strategy for GLM. Subsequently, we identified the pathogenic factor as a new type of glycolipid (named corynekropbactins) secreted by C. parakroppenstedtii. Corynekropbactins may chelate iron, cause the death of mammary cells and other mammary -gland-colonizing bacteria, and increase the levels of inflammatory cytokines. We further analyzed the prevalence of C. parakroppenstedtii infection in patients with GLM. Finally, we suggested that the lipophilicity of C. parakroppenstedtii may be associated with its infection route and proposed a possible model for the development of GLM. This research holds significant implications for the clinical diagnosis and therapeutic management of GLM, offering new insights into targeted treatment approaches.

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).

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.

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

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

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

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

Clinical characteristics and microbiota analysis of 44 patients with granulomatous mastitis

Introduction

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

Methods

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

Results

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

Discussion

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

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.

Characteristics and Management of Granulomatous Lobular Mastitis Associated with Antipsychotics-Induced Hyperprolactinemia

Background: Granulomatous lobular mastitis (GM) is a rare inflammatory breast disease. Reports focusing on GM caused by antipsychotic-induced hyperprolactinemia (HPRL) are very rare. Aim: To report a study of GM associated with antipsychotic-induced HPRL and discuss the mechanism and management. Materials and Methods: A retrospective review of patients with GM and psychiatric disorders were carried out. The clinical characteristics, management and outcome were collected and analyzed. The relationship between antipsychotics and GM was evaluated using the Naranjo Adverse Drug Reaction Probability Scale (Naranjo scale). Results: Nineteen female GM patients with psychiatric diseases, aged 21-39 years, who had received antipsychotics for 0.5-10.2 years were included. Most patients took multiple antipsychotics, and 10 (52.6%) took risperidone-containing regimens. Increased prolactin (PRL) was detected in all patients (range 35.15-200 ng/mL). The scores of Naranjo scale were 7-8, indicated the antipsychotics probably induced GM. All patients received systemic therapy, and were prescribed bromocriptine. Seven patients (36.8%) decreased the dose of antipsychotics, six (31.6%) switched antipsychotics, three (15.8%) continued the primary antipsychotics, and three (15.8%) discontinued antipsychotics. In addition, 14 patients (73.7%) received corticosteroid, 4 (21.1%) received antimycobacterials. PRL decreased to normal in 1 month. Seven patients (36.8%) received excisional surgery. After 12 months' follow-up (range 9-56 months), only three patients (15.8%) had a recurrence. Conclusion: Long-term use of antipsychotics may increase PRL levels, and lead to GM. It is vital to assess PRL level and reduce PRL to normal in patients with GM.

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.