Review of Mammographic and Sonographic Features of an Uncommon Inflammatory Breast Disease - Granulomatous Lobular Mastitis

Objective To investigate the value of color Doppler ultrasonography in differential diagnosis of granulomatous lobular mastitis (GLM) and breast cancer. Methods Preoperative sonograms of 45 GLM, 115 invasive ductal carcinoma (IDC) and 90 ductal carcinoma in situ (DCIS) patients were retrospectively analyzed and further confirmed by histopathology. Results The average age of patients in GLM group was obviously younger than those in IDC and DCIS groups(P<0.001). The size of mass lesion in GLM group was significantly larger than those in IDC and DCIS groups(P<0.001). Compared to IDC group, GLM group showed higher detection rate of liquidity area and mammary ductal ectasia (P<0.01), while less lesions with irregular shape, large A/T ratios (≥0.7), calcification, spiculate margin, peripheral hyperechoic zone or posterior echo attenuation (P<0.05). There were more lesions with spiculate margin, liquidity area or axillary lymph node enlargement found in GLM group than in DCIS group (P<0.01), but less calcification (P<0.001). The accordance rate of ultrasonic diagnosis and postoperative histopathology results in 45 GLM patients was 33.3%(15/45). Conclusions GLM shows the characteristic sonographic findings. In addition, there are some differences between GLM and both IDC & DCIS, such as spiculate margin, peripheral hyperechoic zone, blood flow richness and axillary lymph node enlargement. Combined with the clinical data, understanding the sonographic features of GLM is beneficial to its differential diagnosis with breast cancer. Key words: Ultrasonography; Granulomatous mastitis; Diagnosis, differential

Granulomatous lobular mastitis is a rare inflammatory disease of the breast of unknown etiology. Most present as breast masses in women of child-bearing age. A 29-year-old female presented with a swollen, firm and tender right breast, initially misdiagnosed as mastitis. Core needle biopsy revealed findings consistent with granulomatous lobular mastitis, and cultures were all negative for an infectious etiology. She was started on steroid therapy to which she initially responded well. A few weeks later she deteriorated and was found to have multiple breast abscesses. She underwent operative drainage and cultures grew Mycobacterium fortuitum. Granulomatous lobular mastitis is a rare inflammatory disease of the breast. The definitive diagnose entails a biopsy. Other causes of chronic or granulomatous mastitis should be ruled out, including atypical or rare bacteria such as Mycobacterium fortuitum. This is the first reported case of granulomatous mastitis secondary to Mycobacterium fortuitum. With pathologic confirmation of granulomatous mastitis, an infectious etiology must be ruled out. Atypical bacteria such as Mycobacterium fortuitum may not readily grow on cultures, as with our case. Medical management is appropriate, with surgical excision reserved for refractory cases or for drainage of abscesses.

Granulomatous lobular mastitis is a rare chronic breast disease, firstly described by Kessler and Wolloch in 1972. In this article we present a 35-year-old patient with granulomatous lobular mastitis and in situ ductal carcinoma and discuss clinicopathological characteristics of the disease with literature data. A 35-year-old female patient admitted to the outpatient clinic with a complaint of swelling in right breast ongoing since March 2017. On the basis of physical examination and radiological examinations, antibiotic therapy was initiated considering the inflammatory breast disease and the patient was referred to our general surgery clinic because she did not benefit from treatment. On the recommendation of histopathological correlation, trucut biopsy was performed and reported as granulomatous mastitis. In the histopathological examination of the prepared sections, we found lobule-restricted, non-caseous granulomas and neoplastic epithelial cell proliferation in 4 different foci, the largest being 0.7×0.4 cm in diameter, limited to the ductal lobular system. The case was diagnosed as granulomatous lobular mastitis and in situ ductal carcinoma. This lesion, which clinically and radiologically can be confused with carcinoma, rarely coexists with breast carcinoma. Our case demonstrates the coexistence of granulomatous lobular mastitis and in situ ductal carcinoma.

Objective To investigate the effectiveness of glucocorticoids in the treatment of granulomatous lobular mastitis (GLM), and to discuss the optimal stage to add glucocorticoids during the treatment. Methods Twenty-four patients having received the core needle biopsy were involved. Ten cases with the explicit pathological diagnosis received the glucocorticoids therapy following the subtotal excision after remission. Pathological diagnoses of the rest 14 patients were undefined. For these 14 patients, simple partial excisions were given and the postoperative pathological diagnoses were presented as the GLM. Of all the 14 patients who accepted the surgical treatment firstly, 8 patients received the postoperative glucocorticoids adjuvant therapy. For the rest 6 patients, steroid hormone therapy was not used after surgery, and they were followed up postoperatively. All patients' clinical and pathological information were collected and analyzed. Results All patients were followed up for 6-36 months (average 18) by the outpatient service. Of all the 10 patients who received the glucocorticoids therapy before surgery, only 1 patient of them got the GLM recurrence. For the 8 patients who received the postoperative glucocorticoids treatment, only 1 patient got the recurrence. For the 6 patients who received simple partial excision, the recurrence of the GLM may be up to 3. There was no statistical difference between the two groups who both received the glucocorticoids therapy preoperatively and postoperatively (P>0.05). But compared with the pure surgery treatment, the difference was obviously (P<0.05). Conclusions The clinical presentation and imaging performance of GLM are unspecific, so the diagnosis of the GLM is difficult. There is no consensus regarding the optimal treatment for GLM. The glucocorticoids therapy may be necessary preoperatively or postoperatively. For the patient with clear preoperative biopsy diagnosis, preoperative glucocorticoids adjuvant chemotherapy followed by the wide excision may be an effective method. Key words: Granulomatous lobular mastitis; Diagnosis; Glucocorticoids; Operation

A 36-year-old Hispanic woman presented to University Hospital for further evaluation of a mass in her left breast. The mass had been present for 5 months and was painful. The past medical history was significant for human immunodeficiency virus disease, end-stage acquired immunodeficiency syndrome (CD4 count of 99 cells/mm3 and a viral load of 200,000 copies/μL), hepatitis B and C, syphilis, cytomegalovirus infection, left-sided blindness, and multiple lung nodules. There was no family history of breast cancer. Physical examination revealed a palpable 2-cm mass in her left breast. The initial workup, including mammography and a core biopsy of the mass, was performed at another hospital. The mammogram revealed a suspicious asymmetrical density at 7 o'clock. An excisional biopsy was performed at our institution and the specimen was submitted for pathologic and microbiologic evaluation.Gross examination revealed adipose tissue containing a 2.5 × 1.0 × 1.0-cm circumscribed mass that was firm and gray-tan in color. Histologic examination showed breast tissue with necrotizing granulomatous inflammation (Figure 1). The lobules contained necrotic debris and were diffusely infiltrated by epithelioid histiocytes, lymphocytes, plasma cells, occasional multinucleated giant cells, and polymorphonuclear leukocytes. Histiocytes containing multiple intracellular organisms with peripheral clearing were identified with hematoxylin-eosin stain (Figures 2 and 3). Yeast forms with narrow-based buds and nonbudding yeast forms measuring 2 to 4 μm were noted with Grocott-Gomori methenamine-silver stain (Figure 4). A similar granulomatous process was found in a biopsy of lung nodule samples. The histologic findings were confirmed with microbiologic cultures.What is your diagnosis?Histoplasma capsulatum is a thermal dimorphic fungus found primarily along the major river valleys in parts of North America. It is contracted by the inhalation of fungal spores, and infrequently causes clinical disease. Histoplasma capsulatum is an extremely rare cause of granulomatous mastitis. The organism causes a necrotizing granulomatous inflammation of the breast lobules; 2- to 4-μm yeast forms of the organism are seen within histiocytes. The definitive diagnosis is made by several mechanisms, including microscopic examination, microbiologic culture, antigen detection, and serologic tests. The main differential includes other fungal infections, Mycobacterium tuberculosis, sarcoidosis, and idiopathic granulomatous mastitis. Treatment of H capsulatum granulomatous mastitis is complete excision followed by antibiotic therapy.Granulomatous mastitis secondary to Histoplasma capsulatum is an infrequently reported entity that has been documented in women ranging from 21 to 74 years of age.1–3 Typically, the patient presents with a history of a gradually increasing unilateral breast mass. There may be overlying skin retraction and/or inflammation. There has been a report of 1 patient who also presented with axillary lymphadenopathy.2 A common mammographic finding is an asymmetrical density with a thickening of overlying skin. This dense area may be clinically and radiographically difficult to distinguish from breast cancer.1–3 The definitive diagnosis of H capsulatum is made by several mechanisms, including antigen detection in body fluids, microscopic examination of tissue and blood, isolation and characterization of the fungus in culture, and serologic tests.4The gross examination shows a firm, whitish tan, and focally necrotic mass with surrounding adipose tissue. Histologic examination reveals a necrotizing granulomatous inflammatory process involving breast lobules. The inflammatory infiltrate is composed of polymorphonuclear leukocytes, mononucleated and multinucleated epithelioid histiocytes, lymphocytes, and, occasionally, eosinophils. Histiocytes containing intracellular fungi that are morphologically consistent with H capsulatum are seen with Grocott-Gomori methenamine-silver stain, are not identified with mucicarmine staining, and occasionally demonstrate a periodic acid–Schiff reaction.2 The organism may exhibit a peripheral clearing fixation artifact on hematoxylin-eosin sections and may demonstrate narrow-based budding in the yeast form.3Histoplasma capsulatum is a thermal dimorphic fungus. It is found along the major river valleys in the temperate part of North America, and has also been reported in parts of South America, Europe, Africa, and Asia.45 Histoplasma capsulatum is contracted by the inhalation of fungal spores. In the United States, 90% to 95% of infections are asymptomatic. Clinical disease comes in 3 forms: acute pulmonary, chronic pulmonary, and disseminated. Disseminated disease, the most serious of these forms, is more likely to occur in immunocompromised individuals and those who are at the extremes of age.5 The most common sites of involvement are the spleen and liver. The adrenal gland and central nervous system are 2 of the most critical sites of presentation.46The main differential diagnosis of granulomatous mastitis secondary to H capsulatum includes other fungal infections, Mycobacterium tuberculosis, sarcoidosis, and idiopathic granulomatous mastitis. Clinical correlation as well as laboratory and radiographic studies are important in determining the correct diagnosis. Fungal organisms likely to be confused with H capsulatum in tissue sections include yeast forms of Torulopsis glabrata and Blastomycosis dermatitidis.35 Torulopsis glabrata is primarily an extracellular organism and does not exhibit a peripheral clearing fixation artifact with hematoxylin-eosin stain.3 Blastomycosis dermatitidis is a multinucleated fungal spore that demonstrates broad-based budding.5 Necrotizing granulomas are present in M tuberculosis. Acid-fast organisms are identified by Ziehl-Neelsen stain, microbiologic culture, or molecular techniques. In sarcoidosis, there are nonnecrotizing, well-circumscribed small granulomas with an associated lymphocytic infiltrate and a lack of abscess formation.7Idiopathic granulomatous mastitis has also been described as granulomatous lobular mastitis. In 1972, Kessler and Wolloch8 introduced the term granulomatous mastitis to describe nonspecific lobular granulomatous inflammation occurring in the absence of a known contributory cause. Since then, approximately 120 cases of granulomatous mastitis have been reported worldwide.9 Some proposed causes of this disease include autoimmunity, undetected organisms, oral contraception use, and a localized immune response to extravasated secretions associated with parturition and lactation.110Treatment of H capsulatum granulomatous mastitis is complete excision followed by initial treatment with amphotericin B. Continued maintenance treatment with itraconazole, fluconazole, or amphotericin B is necessary for the treatment of disseminated histoplasmosis to decrease relapse.6

PurposePeriductal mastitis (PDM) is a chronic inflammatory lesion of the breast with an unknown etiology, and it is difficult for clinicians to differentiate it from granulomatous lobular mastitis (GLM), although they have different treatment strategies and prognosis. This study aimed to investigate the differences in their clinicopathologic features to inform treatment strategies.Patients and MethodsBetween 2011 and 2020, 121 patients diagnosed with PDM and 57 patients with GLM were retrospective analysis. Patient data were extracted on demographics, clinical presentation, pathologic characteristics, treatments and clinical response. Histopathological evaluations were performed on core needle biopsy specimens. Immunohistochemical stains using antibodies against CD3, CD4, CD8, CD20, and CD138 was performed to define immune cell infiltration.ResultsPDM patients had a higher median age compared to GLM patients (38 vs 32, p<0.001). PDM was primarily located in the areolar area, while GLM predominantly affected the peripheral quadrant of the breast (56.20% vs 75.44%, p<0.001). Histopathologically, more ductal dilatation (90.08% vs 3.51%, p<0.001), ductal wall thickening (47.93% vs 1.75%, p<0.001), and ductal rupture (44.63% vs 5.26%, p<0.001) were observed in PDM. GLM presented with significantly more granuloma (94.74% vs 10.74%, p<0.001), microabscess (68.42% vs 28.93%, p<0.001), and lipid vacuole (40.35% vs 8.26%, p<0.001) formation than PDM. Immunohistochemical analysis revealed a significant presence of CD20+ B lymphocytes in PDM and a higher prevalence of CD8+ T lymphocytes in GLM, indicating differing immune responses. Treatment outcomes varied, with PDM patients responding well to surgery and anti-mycobacterial therapy, while GLM patients showed favorable responses to steroid therapy.ConclusionPDM is a specific entity with a similar clinical presentation but distinct histopathological features and immune profiles to GLM. Further research is needed to elucidate the pathogenesis and optimize therapeutic approaches for these breast inflammatory conditions.

In recent years, there is a growing incidence of granulomatous lobular mastitis (GLM), butstudies about the coexistence of erythema nodosum (EN) and GLM are rare. In this study, we assess the clinical characteristics and predictive factors of EN in GLM. A total of 303 patients diagnosed with GLM were enrolled from January 2012 to October 2018 at the second affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, including 78 patients with EN. Follow-up data included: lesion site, lesion size, therapy approaches, course of GLM, course of EN, the recurrence of disease, possible causes. All patients had pathologic confirmation of GLM based on core needle biopsy (CNB) or surgical excision. Fever in the EN group was significantly more common compared to the non-EN group (44.87% vs 12.89%, P<0.001). The proportion of lesion range >2 quadrants in the EN group was significantly higher than that in the non-EN group (42.31% vs 16.00%, P<0.001). The course of the disease was longer in the EN group compared to the non-EN group (10.32 moths vs 8.74 moths, P<0.001). Patients with EN had a trend towards a higher risk of recurrence (5.13% vs 1.33%, P=0.055). EN is more likely to be found in GLM patients with breast lesion range >2 quadrants. The presence of EN in GLM indicates that the condition becomes more severe and the course of GLM also becomes longer.

We report a case of a rare inflammatory disease, granulomatous lobular mastitis. Two weeks prior to admission the patient, a 43 year-old woman, (gravida 1, para 1) had noticed a left breast mass associated with tenderness. Palpation, gross inspection, and clinical examination, as well as the rapid growth of the mass lesion led us to believe that it was highly suspicious of malignant neoplasm. Mammography, ultrasonography, and computed tomography did not differentiate it from a malignant neoplasm. Aspiration cytology revealed an inflammatory lesion with a few clusters of epithelial cells it was diagnosed as borderline malignancy(class III) by a prudent pathologist, and thus mastectomy was performed. However, the final histologi-cal diagnosis was granulomatous lobular mastitis with no evidence of malignancy. As the clinical manifestations of granulomatous mastitis are similar to those of mammary carcinoma and, as it is an inflammatory lesion of uncertain etiology and pathogenesis, it has often been mistaken clinically for carcinoma and treated as such. Our review of the literature indicated that granulomatous mastitis most often occurs in young patients with a history of childbirth or oral contraceptive usage. Recurrence was documented in 38% of patients, and, accordingly long-term follow-up by aspiration cytology, complete resection, and adequate drug treatment with corticosteroids are recommended.

Objective To investigate the effect of the ultrasonography-guided abscess puncture aspiration or drainage combined with local application of triamcinolone acetonide in the treatment of granulomatous lobular mastitis (GLM) . Methods The clinical data of forty-six severe GLM patients from February 2015 to February 2017 were analyzed. Twenty-three patients were treated with the ultrasonography-guided abscess puncture aspiration and irrigation (control group), and the other 23 patients were treated with triamcinolone acetonide injection 40 mg from the pinpoint or a drainage tube into the abscess cavity, pressure dressing, 2 times a week after the routine abscess puncture aspiration and irrigation treatment (observation group). The recovery rate, onset time, hospitalization days and patient satisfaction were compared between two groups, and hormone related adverse reaction of observation group was observed. Results There were 17 cases with effective treatment and 1 cured case in the observation group, while 10 cases with effective treatment, no cured case and 1 case lost in control group, with statistical difference (χ2=5.15, P=0.023). Compared with the control group, the observation group had faster onset time, fewer days of hospitalization, and higher satisfaction of the patients (t=5.81, 5.80, χ2=8.09, P<0.01, <0.01, 0.004). The observation group had no obvious hormone-related adverse reactions, whereas 6 patients in the control group had side effects, which gradually disappeared after the cessation of treatment. Conclusion The ultrasonography-guided percutaneous aspiration and drainage combined with local application of triamcinolone acetonide is a choice for clinical treatment of severe GLM. Key words: Granulomatous mastitis; Carcinoma, lobular; Paracentesis; Triamcinolone acetonide

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.

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.

The findings of preoperative ultrasonography in patients with granulomatous lobular mastitis treated in Xintai People′s Hospital from December 2013 to December 2016 were retrospectively analyzed. Among 15 cases of granulomatous lobular mastitis confirmed by pathology, there were 6 cases of mass type, 5 cases of tubular type and 4 cases of mixed type diagnosed by ultrasound before operation, which were consistent to pathological diagnosis in 3, 4, 3, respectively. On the ultrasound images, the blood flow signals are more rich, the tubular and mixed type have certain specificity, and color Doppler flow imaging (CDFI) usualy can make correct diagnosis. For the atypical mass lesions, the final diagnosis can be made by ultrasound-guided needle aspiration biopsy. Key words: Granulomatous mastitis; Ultrasonography

Sometimes, mastitis needs to be differentiated from carcinoma because of its association with induration and with ultrasound findings (such as low-echo lesions) that resemble those in carcinoma. The aim was to define this type of mastitis and to examine 18 cases to clarify its clinicopathological features. All cases were categorized into three types: non-specific mastitis with neutrophilic infiltration (n = 7); non-specific mastitis with lymphoplasmacytic infiltration (n = 9); and granulomatous lobular mastitis (n = 2). The three types of mastitis presented similar ultrasound findings and shared certain histological features including fibrosis and diffuse or lobulocentric inflammation. Granulomatous lobular mastitis showed specific clinicopathological features including lobulocentric inflammation with giant cells, diffuse IgG4+ plasma cells, and also a high level of serum IgG4. Granulomatous lobular mastitis could be categorized into IgG4-related and non-IgG4-related granulomatous lobular mastitis. IgG4 immunohistochemistry serum IgG4 might be useful for diagnosis of IgG4-related granulomatous lobular mastitis and could help to avoid overtreatment such as wide excision.

Granulomatous lobular mastitis (GLM) and mammary duct ectasia (MDE) are inflammatory diseases. However, only a limited number of studies have focused on characterizing their clinicopathological features. The aim of the present study was to investigate the etiology, clinicopathological characteristics and diagnosis of GLM and MDE. The clinical information and treatment of 118 female patients with pathologically-proven GLM or MDE were retrospectively analyzed in the present study. A total of 29 cases had GLM, 77 had MDE and 12 had GLM accompanied by MDE. GLM tends to occur in patients who have had their last birth within 5 years and are usually <40 years of age. GLM masses were usually larger than MDE masses and suppurated or ulcerated more easily. Histopathologically, GLM was characterized by a significant granulomatous inflammatory reaction centered on lobules. Compared with MDE, GLM had a higher incidence of granuloma and microabscess formation within the lobules and surrounding tissue. More multinucleated giant cells within granuloma were observed in patients with GLM than in those with MDE, while MDE was characterized by significant dilatation of the duct terminals and inflammatory changes in the duct wall and periductal tissues. When compared with patients with GLM, foam cells within the duct epithelium or surrounding stroma were more common in patients with MDE. The present study demonstrated that GLM and MDE had distinct clinicopathological characteristics. Further research is required in order to identify more appropriate treatment strategies for these specific types of breast inflammation.

The exact etiology and pathogenesis of granulomatous lobular mastitis (GLM) are yet to be illuminated. This study aimed to investigate CD68, CD163-positive M2 macrophages, CD57-positive natural killer (NK) cells, and IgG4 in GLM lesion tissue to explore their correlation with the occurrence and clinical features of GLM. Surgical pathologic specimens of GLM were collected from patients admitted to Hunan Provincial People's Hospital between October, 2014 and October 2015. Based on the postoperative pathological diagnosis, the tissues were divided into 3 groups: the experimental group (GLM, n=36), control group 1 (plasma cell mastitis, PCM, n=17), and control group 2 (breast cystic hyperplasia, n=10). Immunohistochemical staining was carried out using Elivision super testing to detect CD68, CD163, CD57, and IgG4 expression in the pathological tissue samples. The relationship between clinical parameters, including age, reproductive condition, nipple retraction, and tumor size, and the expressions of CD68, CD163, CD57, and IgG4 was analyzed. There was no obvious difference in the levels of CD68, CD163, and CD57 expression between the GLM group and the PCM group, although both groups had higher expression levels of expression than the breast cystic hyperplasia group (P<0.05). In the GLM group, the expression level of CD57 at 2 weeks-3 months was significantly higher than at ≤2 weeks (P<0.05). The expression level of CD57 in PCM patients >2 years after lactation was significantly higher than in patients ≤2 years after lactation (P<0.05). The level of IgG4 expression in GLM patients with nipple retraction was significantly higher than in those without nipple retraction (P<0.05). Inflammatory cells are closely linked to the occurrence of GLM and PCM. In our study, both the GLM and PCM groups had low expression of IgG4, but the expression level of IgG4 in GLM patients with inverted nipples was significantly higher than that in patients without inverted nipples. This suggests that there may be two different clinical subtypes of GLM. Furthermore, our research also found that NK cells can provide a basis for GLM clinical staging.