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.

Recurrent Idiopathic Granulomatous Mastitis: A Case Report

Idiopathic granulomatous mastitis is a rare benign breast disease of unknown aetiology mostly presenting as a breast abscess but not responding to usual conservative management with incision and drainage and frequently mimics breast cancer. We present a case 31-year-old female presented with complaints of right breast pain and redness who was initially diagnosed and treated as a case of breast abscess with repeated incision and drainage and antibiotics but did not improve. Later histopathology revealed granuloma with giant cell reaction and the patient was given a trial of steroids which showed no improvement. Wide local excision with a long course of broad-spectrum antibiotics was performed which led into remission. This case report highlights the importance of considering idiopathic granulomatous mastitis as differentials in non-responding breast abscesses. Histopathology for diagnosis and trial of wide local excision with a long course of broad-spectrum antibiotics as treatment may be done for management.

Keywords

antibiotics; case reports; granuloma; mastitis.

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.

Granulomatous Mastitis Occurring during Pregnancy: A Case Report

Background and Objectives: Granulomatous mastitis is a benign disease with a clinical presentation similar to that of breast cancer, and is most commonly observed in women of childbearing age. Although it has been suggested that autoimmune diseases are involved in its pathogenesis, no specific treatments have been established. The occurrence of this disease during pregnancy has rarely been reported. We presented the case of a 37-year-old woman who complained of left breast induration at 24 weeks' gestation. Materials and Methods: She was pregnant and manifested a dichorionic, diamniotic placenta. At 24 weeks of gestation, the patient experienced a sensation of hardness in her left breast. Mastitis was suspected, and she was treated with cephem antibiotics. Simultaneously, she was diagnosed with erythema nodosum in the extremities. As her symptoms did not improve, an incisional drainage was performed. Bacterial cultures were obtained at 31 weeks of gestation, and Corynebacterium kroppenstedtii was detected. Results: An elective cesarean section was performed at 37 weeks of gestation, and the baby was delivered safely. After delivery, a needle biopsy was performed, and the patient was diagnosed with granulomatous mastitis. She was completely cured with prednisolone after weaning. In this case, the patient's condition was maintained through incision and drainage, as well as antibiotic, anti-inflammatory, and analgesic drugs during pregnancy. This approach was chosen, taking into consideration the potential side effects of steroids. Conclusions: This case suggests that incisional drainage and antibiotic therapy, as well as steroids and surgery, may be considered in the treatment of granulomatous mastitis occurring during pregnancy. This may also be true for management during delivery. After delivery, breastfeeding and steroidal therapy proved to be effective in treating the condition.

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

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Idiopathic granulomatous mastitis: Risk factors and management

BACKGROUND

IGM has a diagnostic and treatment dilemma. The etiology of IGM is unknown but some conditions have been discussed as predisposing factors including Oral Contraceptive Pills, pregnancy, breast feeding, reproductive age, hyperprolactinemia, infectious and autoimmune diseases. The current study aimed to determine possible risk factors for IGM and to evaluate our experience in its management.

PATIENTS AND METHODS

The study included forty patients with IGM and forty females with normal breasts as a control group. CST treatment was initiated for all patients; patients who responded completely were followed up without surgical intervention. Failure to respond to medical therapy or incidence of corticosteroid-related complications were considered indications for surgical treatment. All patients were followed up for 6 months to detect recurrence.

RESULTS

IGM had a significant higher incidence rate in young females within 5 years from the last lactation, smokers, those with hypperprolactinaemia, who had a history of breast feeding and those who received OCP (P = <0.001, <0.001, 0.006, 0.001, 0.023 and 0.027 respectively). The central part of the breast was more affected (9 cases (22.5%)). Multicenteric disease affected 8 cases (20%). Breast Mass was the most common presenting sign. After CST; the mass disappeared in 5 cases (12.5%), mass size reduced in 26 cases (65%) and mass size not affected in 9 cases (22.5%). Surgery was done in whom the mass size was reduced or not affected (35 cases (87.5%)). Disease recurrence was reported in 2 cases (5.7%).

CONCLUSION

IGM usually affects females in their childbearing period with multiple risk factors mainly parity, smoking, OCP and breast feeding with wide variation regarding the presenting manifestations. We should start with CST as there is always a chance to avoid unnecessary surgery and combination of both modalities can reduce the incidence of recurrence.

The therapeutic dilemma of idiopathic granulomatous mastitis

INTRODUCTION

Idiopathic granulomatous mastitis (IGM) is a rare, benign, chronic breast condition that can cause repeated abscesses or mass formation in bilateral breasts. The condition can severely impact the quality of life of affected women. This study aims to evaluate effective treatment modalities, as well as understand the demographics and clinical presentation of patients with IGM.

METHODS

An 11-year retrospective review was performed of patients diagnosed with IGM from 1 January 2008 to 31 December 2018 at a tertiary breast unit.

RESULTS

A total of 77 patients were included in the study. The median age at presentation was 36 years old. IGM presented most commonly as a breast lump (98.1%). The median number of flares was 2 (1-12). Of the 77 patients, 68.8% (53) were treated with antibiotics, 50.6% (39) with steroids, and 44.2% (34) underwent surgery, in the course of their IGM treatment. Forty-five (59.2%) of the 76 patients with IGM required a multimodal treatment approach to achieve remission. There was no significant difference in the number of flares no matter the initial treatment (P=0.411), or subsequent treatment modality (P=0.343). Smokers had 10 times greater odds of having a "high flare" of IGM compared to those who did not smoke (P=0.031, odds ratio 10.444, 95% confidence interval 1.092-99.859).

CONCLUSION

IGM is a clinical diagnosis. It is a rare, relapsing breast inflammatory condition that affects young females with no superior treatment modality. Smoking is associated with higher number of flares of IGM and should be discouraged in IGM patients.

Granulomatous mastitis in multiparae during pregnancy and lactation: Observational study (STROBE compliant)

The incidence of granulomatous mastitis (GLM) in multiparae as seriously affected the quality of life and breastfeeding of pregnant women after delivery, but the treatment is rarely reported. In this article, the development, healing, and lactation of 13 cases were reported and a retrospective analysis was performed. 10 cases of GLM were treated at the Breast Disease Prevention and Treatment Center of Haidian Maternal & Child Health Hospital of Beijing and 3 cases of GLM were treated in the Breast Department of Weihai Municipal Hospital of Shandong province from February 2017 to May 2019.Among the 13 patients, conservative symptomatic treatment was adopted during pregnancy and lactation: anti-infective therapy consisting of oral cephalosporin antibiotic for patients; ultrasound-guided puncture and drainage of pus or incision and drainage after abscess formation. Observation continued during the sinus tract phase. Postpartum breastfeeding was encouraged, especially on the affected side. In this study, the median healing time was 20 months and the average healing time was 30.4 months in 5 healthy breast lactation cases. In 8 cases of bilateral breast lactation, the median healing time was 30 months and the average healing time was 26.5 months. Linear regression test analysis: whether the affected breast was breast-fed after delivery had no effect on the postpartum wound healing time, P = .792. The wounds of 13 patients healed well after lactation, and none of them recurred since the last follow-up visit. There were no adverse events in all infants.Conservative symptomatic treatment for GLM of multiparous women during pregnancy and lactation and encouraging breastfeeding after delivery have no effect on infant health and the recovery time of patients.

What are the new findings with regard to the mysterious disease idiopathic granulomatous mastitis?

PURPOSE

To review the demographic and clinical features and the success rates of treatment approaches for idiopathic granulomatous mastitis (IGM).

METHODS

A total of 134 patients diagnosed with IGM pathologically and treated by a single breast surgeon were retrospectively analyzed.

RESULTS

The time between the occurrence of symptoms and the last delivery was < 24 months in 25 (23.1%), 24-48 months in 51 (38.1%), and > 48 months in 52 (38.8%). The difference was statistically significant (p = 0.002). Although there was no significant difference, seasonal fluctuations were noticed, with the incidence being slightly higher during late spring and summer. Bilateral disease was present in 10 (7.5%) patients. Seven patients (5.2%) had erythema nodosum. The treatment approaches were conservative in 42, surgical procedures in 48, steroid treatment in 18, and surgical procedure + steroid treatment in 24. The median recovery time with conservative approaches was lower than that with surgical procedure + steroid treatment (p < 0.0001). Recurrence developed in 10 patients (7.7%).

CONCLUSION

Clinical differences were detected among the patients with IGM, and classification of patients by severity is needed to plan the optimal treatment approach. Seasonal fluctuations suggest the possibility of an immunological disease rather than a surgical disease.

Idiopathic granulomatous mastitis

Idiopathic granulomatous mastitis (IGM) is a rare, poorly understood condition that presents as inflammatory nodules of the breast. It is often initially misdiagnosed as furunculosis or cellulitis. Despite the painful, scarring, and debilitating nature of the disease, patients often have a delay in accurate diagnosis and treatment. Even when IGM is considered as a diagnosis, it is one of exclusion, with the differential diagnosis including serious conditions such as breast cancer, sarcoidosis, and cutaneous tuberculosis. Therefore, appropriate workup is important. Given that IGM is a disease of the skin, it is important for dermatologists to be familiar with its presentation. We describe 3 cases of young women with this condition and demonstrate that identification of triggers or methotrexate treatment is highly successful in sparing patients the drastic surgical alternative of mastectomy.

Granulomatous Lobular Mastitis

BACKGROUND

Granulomatous lobular mastitis (GLM) is a rare disorder that can clinically mimic breast carcinoma. The recommendation for diagnosis and treatment of GLM has not yet been established.

OBJECTIVES

To assess a series of GLM patients, including their clinical presentation, diagnosis, treatment and outcome.

METHODS

We retrospectively analyzed the clinical data and treatment of 17 female patients with biopsy-proven GLM. Breast tissue was obtained by a core needle biopsy (15 patients) or open biopsy (2 patients). Images were reviewed by an experienced radiologist.

RESULTS

The mean age of the patients at diagnosis was 44.6 ± 12.6 years. Five patients (29%) presented with bilateral disease, and seven (41%) presented with a mass, suggesting the initial diagnosis of breast carcinoma. Treatment comprised observation alone (23%), antibiotics (58.8%) and/or corticosteroids (with or without methotrexate) (35%). At the end of the study 70.6% of the patients demonstrated complete remission. None of the patients developed any systemic (granulomatous) disease or breast carcinoma during the follow-up period (4.7 ± 3.8 years).

CONCLUSIONS

Core needle biopsy is mandatory for the diagnosis of GLM and the exclusion of breast carcinoma. The recommended treatment modalities are observation alone or corticosteroids; surgery should be avoided. GLM is a benign disease with a high rate of resolution and complete remission.

Breast lumps: a rare site for rheumatoid nodules

Granulomatous mastitis (GM) of the breast is a rare benign inflammatory disease and its presentation closely mimics breast cancer. Its diagnosis is mainly based on histology and there is no consensus agreement regarding its management. We report a case of a 60-year-old woman presenting with a right breast lump associated with a history of rheumatoid arthritis and raised rheumatoid factor. Following triple assessment (history and examination, imaging and biopsy), GM was diagnosed and she was treated conservatively.

Management of idiopathic granulomatous mastitis with observation

BACKGROUND

Idiopathic granulomatous mastitis (IGM) is becoming more commonly recognized and reported more often. Currently, many recommend corticosteroids in its management.

METHODS

A retrospective chart review was conducted from January 2002 to June 2013. Data were collected regarding sociodemographic information, clinical history, treatment, and outcomes.

RESULTS

Thirty-seven patients were found with IGM. Thirty-five patients were Hispanic born outside the United States. Early in the time period reviewed, 5 patients had masses excised and 5 patients were lost to follow-up. Twenty-seven cases of IGM resolved with observation. Corticosteroids were not used in the management. The average time to resolution was 7.4 months. Three patients (11%) had recurrent episodes after resolution.

CONCLUSIONS

IGM is a self-limited benign condition that will resolve spontaneously without treatment. Patience with the natural history of IGM is important, as the process often includes periods of exacerbation before resolution.

Idiopathic granulomatous mastitis. Experience at a cancer center

BACKGROUND

Idiopathic granulomatous mastitis (IGM) is a benign breast disease that has been described as a rare granulomatous inflammation (GI). It can mimic inflammatory breast cancer.

MATERIAL AND METHODS

We included women with a diagnosis of IGM referred to an oncologic hospital between January 01, 2007 and to March 31, 2011, with diagnosis of breast cancer, in whom biopsy reported GI, without other cause related. The aim of this study was to review the clinical, radiologic and pathologic characteristics of a cohort of women with IGM.

RESULTS

We analyzed 58 patients; mean age was 38 ± 12 years. Mammography showed diffuse asymmetry (n = 19) and focal asymmetry (n = 13); breast ultrasound showed heterogeneous and hypoechoic areas (n = 28) and lumps (n = 21) as the most frequent lesions. All biopsies showed lobulocentric GI. Treatment included antibiotics (n = 20), steroids (n = 8), both treatments (n = 20), surgical excision (n = 3) and observation (n = 7). Forty-three patients (74%) had complete remission; mean time to remission was 9.5 ± 5.8 months. Fifteen (26%) had partial remission. Any patient had progression or relapse.

CONCLUSIONS

IGM is a benign breast condition that may mimic breast inflammatory cancer. Ultrasonography and mammography findings reveal characteristic data that can be useful for establishing the diagnosis; however, biopsy is the gold standard for its diagnosis and should be taken in any patient even with a mild suspicion of cancer.

Long-term outcome in idiopathic granulomatous mastitis: a western multicentre study

AIM

To investigate the presentation, disease course and long-term outcome of a western cohort of idiopathic granulomatous mastitis (IGM) and to analyse the impact of different therapeutic strategies.

METHODS

Multicentre retrospective study of 23 women followed over an extended period. Patients were recruited in nine French internal medicine departments.

RESULTS

The median follow-up was 6 years. IGM presented commonly as a single inflammatory unilateral extra-areolar lump of varying size. Clinical course was heterogeneous and frequently remitting/relapsing. Most patients had at least one recurrence (18/23, 78%). The mean number of recurrences was 1.3 ± 1.5. Seven women had a bilateral evolution. Twelve women received steroids (corticosteroids). Only two of these did not respond to corticosteroids, whereas six relapsed when dose was tapered off. Nine patients received colchicine and/or hydroxychloroquine. First-line treatment consisted of excisional surgery in eight cases. At the date of last interview, 91% of the patients declared to be healed, 15 being free of treatment. However, 12/21 (57%) reported significant sequelae (unsightly scars: eight and/or lasting pain: six). Unsightly scars were not more prevalent in patients who had received steroids whereas they tended to be more frequent after breast excisional surgery. In addition, we found that excisional surgery did not prevent recurrences more successfully than a conservative approach.

CONCLUSIONS

Despite its retrospective nature, this Caucasian series provides novel information regarding long-term outcomes in IGM and argues in favour of conservative approaches. The value of immunomodulatory drugs such as colchicine or hydroxychloroquine deserves further investigation.

Idiopathic granulomatous mastitis: a report of twenty cases

INTRODUCTION

Idiopathic granulomatous mastitis is a benign lesion of the mammary gland characterised by the presence of non-infectious inflammatory breast lesions limited to the lobules.

OBJECTIVE

We report twenty cases of idiopathic granulomatous mastitis (IGM) with a discussion of epidemiology, clinical and diagnostic features, treatment and progress of this pathological entity.

MATERIALS AND METHODS

A retrospective study of twenty cases compiled from a ten-year period, from 952 pathological anatomy examinations carried out to investigate various breast pathologies.

RESULTS

The patients had a mean age of 45.5 years. Clinical examinations revealed a tumefaction measuring between 2.5 and 18 cm in diameter. The mean size was 5.5 cm. Mammography showed nodular lesions and sonography demonstrated hypoechoic nodules. On histological examination there was a granulomatous inflammatory infiltrate of epithelioid and giant cells, without caseation necrosis, made up of lymphocytes, plasma cells and neutrophils. Microbiology investigations were negative. Lesion involvement was principally lobulocentric. Surgical excision of the lesions was combined with corticosteroid therapy in twelve cases, with non-steroidal anti-inflammatory drugs in another four and with antibiotic therapy in four cases. The patients made good progress in the short-term.

DISCUSSION AND CONCLUSION

IGM is a rare entity. It poses a problem of differential diagnosis because it clinically resembles other forms of mastitis. The diagnosis can be made with certainty on histological studies. The treatment is medical alongside surgical excision. The prognosis of this disease remains favourable.

Idiopathic granulomatous mastitis associated with corynebacterium sp. Infection

Idiopathic granulomatous mastitis (IGM) is a rare inflammatory condition of the breast. The etiology and treatments options of IGM remain controversial. Previous case reports have suggested that Corynebacterium sp., a gram-positive bacillus endogenous to the skin, may be associated with IGM. In the present report, we describe the first case of IGM with a positive culture for Corynebacterium sp. reported in the United States.