Pregnancy Associated Granulomatous Mastitis: Clinical Characteristics, Management, and Outcome

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.

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.

Factors Affecting Recurrence of Idiopathic Granulomatous Mastitis: A Systematic Review

Idiopathic granulomatous mastitis is a rare and benign disease that primarily affects young women of reproductive age. Various factors have been suggested as possible causes, including pregnancy, breastfeeding, history of taking birth control pills, hyperprolactinemia, smoking, and history of trauma. Due to unknown etiology, opinions on its treatment have varied, resulting in differing recurrence rates and side effects. Therefore, conducting a comprehensive systematic review and meta-analysis can aid in understanding the causes and recurrence of the disease, thereby assisting in the selection of effective treatment and improving the quality of life. A systematic literature review was conducted using predefined search terms to identify eligible studies related to risk factors and recurrence up to June 2022 from electronic databases. Data were extracted and subjected to meta-analysis when applicable. A total of 71 studies with 4735 patients were included. The mean age of the patients was 34.98 years, and the average mass size was 4.64 cm. About 3749 of these patients (79.17%) were Caucasian. Patients who mentioned a history of pregnancy were 92.65% with 76.57%, 22.7%, and 19.7% having a history of breastfeeding, taking contraceptive pills, and high prolactin levels, respectively. Around 5.6% of patients had previous trauma. The overall recurrence rate was 17.18%, with recurrence rates for treatments as follows: surgery (22.5%), immunosuppressive treatment (14.7%), combined treatment (14.9%), antibiotic treatment (6.74%), and observation (9.4%). Only antibiotic and expectant treatments had significant differences in recurrence rates compared to other treatments (p value = 0.023). In conclusion, factors such as Caucasian race, pregnancy and breastfeeding history, and use of contraceptive hormone are commonly associated with the disease recurrence. Treatment should be tailored based on symptom severity and patient preference, with surgery or immunosuppressive options for recurrence.

Clinical characteristics and therapeutic strategy of granulomatous mastitis accompanied by Corynebacterium kroppenstedtii: a retrospective cohort study

BACKGROUND

Increasing evidence has suggested that Corynebacterium kroppenstedtii is associated with some cases of granulomatous mastitis, mostly based on pathology or microbiology. We aimed to identify the clinical characteristics and treatment regimens for granulomatous mastitis with Corynebacterium kroppenstedtii infection. Understanding these clinical features is essential for patient care.

METHODS

We retrospectively collected data on 201 patients who were pathologically diagnosed with granulomatous mastitis and had microbiological results of either Corynebacterium kroppenstedtii or no bacterial growth and recorded and analysed their demographics, clinical characteristics, and clinical outcomes.

RESULTS

There were 107 patients in the CK group and 94 patients in the negative group. Sinus formation (x² = 13.028, p = 0.000), time to complete remission at the first treatment period (Z = -3.027, p = 0.002), diameter of breast mass at first-time medical consultancy (Z = -2.539, p = 0.011) and recurrence (x² = 4.953, p = 0.026) were statistically significant. Age (Z = -1.046, p = 0.295), laterality (x² = 4.217, p = 0.121), time to presentation since the last delivery (x² = 0.028, p = 0.868), BMI (Z = -0.947, p = 0.344), lactation time (Z = -1.378, p = 0.168), parity (x² = 1.799, p = 0.180), gravida (Z = -0.144, p = 0.885), history of lactational mastitis or abscess (x² = 0.115, p = 0.734), local trauma (x² = 0.982, p = 0.322), hyperprolactinemia (x² = 0.706, p = 0.401), erythema nodosum (x² = 0.292, p = 0.589), and nipple discharge (x² = 0.281, p = 0.596) did not demonstrate statistical significance. Regarding recurrence related to therapeutic strategy, except for surgery combined with immunosuppressants (x² = 9.110, p = 0.003), which was statistically significant, none of the other treatment regimens reached statistical significance. The recurrence rate of patients in the CK group using rifampicin in their treatment course was 22.0% (x² = 4.892, p = 0.027).

CONCLUSIONS

Granulomatous mastitis accompanied by Corynebacterium kroppenstedtii more easily forms sinuses and has a higher recurrence rate. Both of the clinical characteristics may indicate that Corynebacterium kroppenstedtii plays an important role in the development and progression of granulomatous mastitis. Lipophilic antibiotics may be essential for granulomatous mastitis with Corynebacterium kroppenstedtii infection.

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.

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.

Granulomatous Mastitis With Erythema Nodosum During Pregnancy: A Case Report

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