Radiological and clinical features of adult non-puerperal mastitis

Research Progress of Plasma Cell Mastitis

BACKGROUND

Plasma cell mastitis (PCM), also termed mammary duct ectasia, is a chronic nonbacterial inflammatory disease characterized by mammary duct dilation and plasma cell infiltration. Due to its varied and nonspecific clinical presentation, PCM is frequently misdiagnosed as breast cancer, complicating clinical management.

OBJECTIVES

This review aims to summarize recent advances in the understanding of PCM, focusing on its etiology, clinical manifestations, diagnosis, and treatment strategies, as well as clarifying differential diagnostic points with granulomatous mastitis (GLM).

METHODS

We reviewed recent literature highlighting clinical characteristics, diagnostic approaches, and therapeutic options related to PCM, including comparative studies addressing differences between PCM and GLM.

DISCUSSION

Recent progress has enhanced understanding of PCM's clinical and pathological features, yet distinguishing PCM from GLM remains clinically challenging due to overlapping presentations. An integrated approach involving clinical evaluation, imaging modalities, and histopathological examination is recommended to improve diagnostic accuracy and clinical outcomes.

CONCLUSION

Further investigation into the pathogenesis of PCM is essential for developing more precise diagnostic criteria and effective treatments, ultimately improving patient prognosis and reducing misdiagnosis.

An update on multimodal imaging strategies for nipple discharge: from detection to decision

Nipple discharge affects over 80% of women at some point in their lives, with malignancy detected in up to 23% of cases. This review highlights the shift from traditional surgical approaches to advanced imaging techniques, which enhance diagnostic accuracy and reduce unnecessary procedures. Diagnosis begins with a thorough medical history and physical examination to assess the need for imaging. Physiological nipple discharge, which is bilateral, multiductal, and non-spontaneous, typically requires no imaging. Conversely, pathological nipple discharge (PND), characteristically unilateral, uniductal, and spontaneous, requires imaging to rule out malignancy. Bloody PND is frequently associated with breast cancer, and up to 12% of non-bloody PND cases also involve malignancy. For women over 40 years, the first-line imaging modality is full-field digital mammography (FFDM) or digital breast tomosynthesis (DBT), usually combined with ultrasound (US). Men with PND undergo FFDM/DBT starting at age 25 years due to their higher risk of breast cancer. For women aged 30-39 years, US is the first assessment tool, with FFDM/DBT added, if necessary, while US is preferred for younger women and men. When initial imaging is negative or inconclusive, magnetic resonance imaging (MRI) is useful, often replacing galactography. With its high sensitivity and negative predictive value of almost 100%, a negative MRI can often obviate the need for surgery. Contrast-enhanced mammography (CEM) offers a viable alternative when MRI is not feasible. Although invasive, ductoscopy helps identify patients who may not require duct excision. This review consolidates the latest evidence and proposes an updated diagnostic algorithm for managing PND effectively. CRITICAL RELEVANCE STATEMENT: Effective management of nipple discharge requires recognising when imaging tests are needed and selecting the most appropriate diagnostic technique to rule out malignancy and avoid unnecessary interventions. KEY POINTS: First-line imaging for pathological nipple discharge (PND) assessment includes ultrasound and mammography. MRI is recommended for patients with PND and negative conventional imaging. A negative MRI is sufficient to justify surveillance rather than surgery. Contrast-enhanced mammography (CEM) is an alternative when MRI is unavailable or contraindicated.

A cohort study of prolactin and non-puerperal mastitis using real world data

Non-puerperal mastitis (NPM) is an umbrella term for non-specific inflammatory mastitis that occurs during the non-puerperal period and has an unclear aetiology. The current study aims to characterize NPM patients and examine the determinants associated with NPM severity. This study analyzed the NPM inpatients admitted to the Department of Breast Surgery, Longhua Hospital Affiliated with the Shanghai University of Traditional Chinese Medicine from 2016 to 2020. We explored NPM patient characteristics through demographics, physical risks, lab tests, and medical history indicators. Multivariable logistic regression was conducted to identify the relationship between the prolactin (PRL) level and NPM severity stratified by breast structure. The majority of NPM inpatients had normal breast structures and were of lower average age than those with congenital nipple deformity (p = 0.002). Significant positive risk (p < 0.001) association between PRL level and NPM severity was observed among NPM inpatients with normal breast structure in both crude and adjusted models (adjusted OR: 2.91; 95%CI:1.88-4.52), with younger age as a protective factor (OR:0.94; 95%CI:0.91-0.97) and smoking history as a risk factor (OR:2.22; 95%CI:1.22-4.05). For NPM patients with nipple deformity, increasing odds of NPM severity regarding higher PRL level was observed while the result is not statistically significant at 0.05 level. (OR: 2.17; 95%CI: 0.94-5.03). The risk of NPM severe episodes is higher among patients with higher PRL levels, of which the association is stronger for NPM patients with normal breast structure, implying different pathogenesis between NPM patients with varied breast anatomy. Disagreement of the interaction effect testification indicates an improvement window for the current study.Trial registration: ChiCTR2000035929. Registered 20 August 2020(retrospectively registered).

Approach to Nonmass Lesions on Breast Ultrasound

Nonmass lesions in breast ultrasound (US) are areas of altered echogenicity without definite margins or mass effect. However, these lesions may show calcifications, associated architectural distortion, or shadowing just like masses. They vary in their echogenicity, distribution, ductal or nonductal appearance and the associated features that can be seen in variety of benign and malignant pathologies. With no uniform definition or classification system, there is no standardized approach in further risk categorization and management strategies of these lesions. Malignant nonmass lesions are not uncommon and few sonographic features can help in differentiating benign and malignant pathologies. US-guided tissue sampling or lesion localization can be preferred in the nonmass lesions identified on second look US after magnetic resonance imaging or mammography. This article aims to describe various imaging patterns and attempts to provide an algorithmic approach to nonmass findings on breast US.

Magnetic resonance imaging findings for inflammatory mastitis of unknown etiology

Inflammatory mastitis of unknown etiology includes the entities periductal mastitis and idiopathic granulomatous mastitis. These relatively uncommon processes usually affect women of childbearing age. They usually present as a palpable mass that is painful on palpation. These lesions have an insidious clinical course and are difficult to diagnose. In some cases, they can resemble malignant disease, especially in some very developed cases where they can resemble inflammatory carcinoma. When considered all together in the appropriate clinical context, the magnetic resonance imaging signs enable us to approach a specific diagnosis. These entities share clinical and radiological characteristics with malignant processes, so biopsies are fundamental to rule out malignancy.

Prediction models for postoperative recurrence of non-lactating mastitis based on machine learning

OBJECTIVES

This study aims to build a machine learning (ML) model to predict the recurrence probability for postoperative non-lactating mastitis (NLM) by Random Forest (RF) and XGBoost algorithms. It can provide the ability to identify the risk of NLM recurrence and guidance in clinical treatment plan.

METHODS

This study was conducted on inpatients who were admitted to the Mammary Department of Shuguang Hospital affiliated to Shanghai University of Traditional Chinese Medicine between July 2019 to December 2021. Inpatient data follow-up has been completed until December 2022. Ten features were selected in this study to build the ML model: age, body mass index (BMI), number of abortions, presence of inverted nipples, extent of breast mass, white blood cell count (WBC), neutrophil to lymphocyte ratio (NLR), albumin-globulin ratio (AGR) and triglyceride (TG) and presence of intraoperative discharge. We used two ML approaches (RF and XGBoost) to build models and predict the NLM recurrence risk of female patients. Totally 258 patients were randomly divided into a training set and a test set according to a 75%-25% proportion. The model performance was evaluated based on Accuracy, Precision, Recall, F1-score and AUC. The Shapley Additive Explanations (SHAP) method was used to interpret the model.

RESULTS

There were 48 (18.6%) NLM patients who experienced recurrence during the follow-up period. Ten features were selected in this study to build the ML model. For the RF model, BMI is the most important influence factor and for the XGBoost model is intraoperative discharge. The results of tenfold cross-validation suggest that both the RF model and the XGBoost model have good predictive performance, but the XGBoost model has a better performance than the RF model in our study. The trends of SHAP values of all features in our models are consistent with the trends of these features' clinical presentation. The inclusion of these ten features in the model is necessary to build practical prediction models for recurrence.

CONCLUSIONS

The results of tenfold cross-validation and SHAP values suggest that the models have predictive ability. The trend of SHAP value provides auxiliary validation in our models and makes it have more clinical significance.

Multimodality Imaging of Benign and Malignant Diseases of the Nipple-Areolar Complex

The nipple-areolar complex (NAC), a unique anatomic structure of the breast, encompasses the terminal intramammary ducts and skin appendages. Several benign and malignant diseases can arise within the NAC. As several conditions have overlapping symptoms and imaging findings, understanding the distinctive nipple anatomy, as well as the clinical and imaging features of each NAC disease process, is essential. A multimodality imaging approach is optimal in the presence or absence of clinical symptoms. The authors review the ductal anatomy and anomalies, including congenital abnormalities and nipple retraction. They then discuss the causes of nipple discharge and highlight best practices for the imaging workup of pathologic nipple discharge, a common condition that can pose a diagnostic challenge and may be the presenting symptom of breast cancer. The imaging modalities used to evaluate and differentiate benign conditions (eg, dermatologic conditions, epidermal inclusion cyst, mammary ductal ectasia, periductal mastitis, and nonpuerperal abscess), benign tumors (eg, papilloma, nipple adenoma, and syringomatous tumor of the nipple), and malignant conditions (eg, breast cancer and Paget disease of the breast) are reviewed. Breast MRI is the current preferred imaging modality used to evaluate for NAC involvement by breast cancer and select suitable candidates for nipple-sparing mastectomy. Different biopsy techniques (US -guided biopsy and stereotactic biopsy) for sampling NAC masses and calcifications are described. This multimodality imaging approach ensures an accurate diagnosis, enabling optimal clinical management and patient outcomes. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Efficacy and safety of rifampicin-based triple therapy for non-puerperal mastitis: A single-arm, open-label, prospective clinical trial

OBJECTIVES

To assess the efficacy and safety of rifampicin-based triple therapy (rifampicin, isoniazid, and ethambutol) for treating NPM.

METHODS

This single-center, single-arm, prospective clinical trial was conducted at the Second Hospital of Shandong University (Jinan, China). Patients with pathologically diagnosed granulomatous lobular mastitis and periductal mastitis received triple drugs, i.e., rifampicin (450 mg/day), isoniazid (300 mg/day), and ethambutol (15 mg/kg/day), until complete response or the investigator decided to discontinue treatment. The primary endpoint was the complete response rate (CRR) assessed by the investigator. The secondary endpoints included the overall remission rate (ORR), recurrence rate (RR), and safety.

RESULTS

A total of 218 patients were enrolled in the study between January 1, 2013 and October 31, 2020. With a median follow-up time of 48 months, the CRR and the ORR were 78.44% and 94.04%, respectively. While 13 patients (5.96%) demonstrated no response and 19 relapsed (8.72%). Adverse events (AEs) were not common. The most common AEs during treatment were liver dysfunction (1.83%), gastrointestinal reactions (1.83%), fatigue (1.83%), erythema (1.38%), and menstrual disorders (0.92%).

CONCLUSION

Rifampicin, isoniazid, and ethambutol demonstrated promising response rates with acceptable safety profiles in patients with NPM. Further confirmatory trial is warranted in the future.

TRIAL REGISTRATION

The study was approved by the Ethics Committee of the Second Hospital of Shandong University and retrospectively registered at the China Clinical Trial Registration Center (registration number: ChiCTR2100049591).

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.

Predictive Significance of the Preoperative Neutrophil-lymphocyte Ratio for Recurrence in Idiopathic Granulomatous Mastitis Patients

BACKGROUND

To investigate and assess the correlation between inflammatory markers, such as the preoperative neutrophil-lymphocyte ratio (NLR), and the recurrence of idiopathic granulomatous mastitis (IGM).

METHODS

All patients with IGM who were free of malignancy or inflammatory diseases were included in this retrospective analysis between January 2013 and December 2019. On the basis of the presence or absence of recurrence, the patients were split into two groups. After collecting retrospective data, the relationship between patient characteristics, hematological markers such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), NLR, platelet-lymphocyte ratio (PLR), and white blood cell count (WBC), and their connection with postoperative recurrence were assessed utilizing univariate and multivariate analyses, receiver operating characteristic curves (ROC curves), and logistic regression.

RESULTS

Recurrences occurred in 40.0% (32/80) of the 80 patients over a median follow-up duration of 35.5 months (22.0-47.8 months). The recurrent group showed higher NLR and CRP than the non-recurrent group (PNLR = .003, PCRP = .02). Neutrophil-lymphocyte ratio and postoperative recurrence were associated (correlation coefficient r = .436, P = .01). The ROC curve's ideal threshold, which had predictive value for IGM recurrence, was 2.18 (sensitivity: 46.9%; specificity: 14.6%).

CONCLUSION

The preoperative NLR is a simple and affordable way to predict IGM relapse, which is important for directing clinical work.

Nipple Discharge: When is it Worrisome?

Nipple discharge is the third most common breast related complaint seen in the breast clinics. Although the majority of cases are due to a benign etiology, 5%-12% cases of pathological nipple discharge may be harboring an underlying malignancy. A thorough radiological workup in cases of pathological nipple discharge is thus of utmost importance, with the initial imaging modality depending on the age of the patient. The imaging modalities include mammogram (MG) and ultrasound (US) with addition of breast MRI if the nipple discharge is clinically suspicious and no MG or US correlate is identified. Magnetic Resonance Imaging (MRI) also holds promise in demonstrating the exact extent of a pathology detected on US and thus aids in the planning of further management.

Inflammatory Lesions of the Breast

CONTEXT.—

Inflammatory lesions of the breast are rare but not infrequently pose problems both clinically and morphologically, particularly on needle core biopsies. These lesions range from acute inflammatory conditions to chronic lymphoplasmacytic and lymphohistiocytic to granulomatous inflammatory diseases.

OBJECTIVE.—

To provide a comprehensive overview of inflammatory lesions of the breast, with etiopathogenesis and clinical, radiologic, and pathologic features as well as differential diagnostic considerations, clinical management, and prognosis.

DATA SOURCES.—

The existing literature in the English language, including original research articles and review articles describing inflammatory lesions of the breast.

CONCLUSIONS.—

Inflammatory lesions of the breast are characterized by a wide variety of clinical, radiologic, and morphologic features. The histopathologic differential diagnosis often includes a neoplastic process requiring ancillary studies and correlation with clinical and radiologic findings. Although most specimens display nonspecific findings precluding a definitive pathologic diagnosis, pathologists have a unique opportunity to play a crucial role in identifying key histologic features suggestive of certain entities, such as cystic neutrophilic granulomatous mastitis, immunoglobulin (Ig) G4 mastitis, or squamous metaplasia of lactiferous ducts, in the right clinical and radiologic context, and thereby guiding optimal and timely clinical management. The information presented herein will be helpful to practicing anatomic pathologists and pathology trainees in becoming more familiar with specific morphologic features and overcoming differential diagnostic challenges related to pathology reporting of inflammatory lesions of the breast.

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.

A Preliminary Study of Ultrasound-Guided Microwave Ablation for Nonpuerperal Mastitis Treatment

Introduction

This study investigated the feasibility of ultrasound (US)-guided microwave ablation (MWA) as a treatment for nonpuerperal mastitis (NPM).

Methods

Fifty-three patients with NPM diagnosed by biopsy and treated with US-guided MWA at the Affiliated Hospital of Nantong University between September 2020 and February 2022 were classified according to whether they underwent MWA alone (n = 29) or MWA with incision and drainage (n = 24). Patients were followed up by interviews, physical and US examinations, and evaluation of breast skin at 1 week and 1, 2, and 3 months after treatment. Data from these patients were prospectively collected and retrospectively analyzed.

Results

The overall mean patient age was 34.42 ± 9.20 years. The groups differed significantly by age, involved quadrants, and the initial maximum diameter of lesions. In the MWA group, the cure rate was 34.48%, and the apparent efficiency rate was 65.52%. In the MWA with incision and drainage, the apparent efficiency rate was 91.66%, and the effective rate was 4.17%. The excellent rate for breast aesthetics in the MWA group was 79.31%, and the good rate was 20.69%. The excellent rate in the MWA with incision and drainage group was 45.83%, the good rate was 41.67%, and the qualified rate was 12.5%. The mean maximum diameter of lesions in the two groups decreased significantly.

Conclusion

For NPM with small lesions in a single quadrant, MWA therapy is a direct and effective method. For larger lesions involving two or more quadrants, the combined treatment of MWA with incision and drainage showed significant improvement in a short period. MWA treatment of NPM has importance for further research and clinical applications.

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.

Case report: A case of acute mastitis associated with reactive cutaneous capillary endothelial proliferation after camrelizumab treatment: A new immune-related adverse event

Lung cancer is a malignant tumor with the highest morbidity and mortality rate worldwide, and it seriously endangers human health. In recent years, immunotherapy has been widely used in lung cancer and has achieved great benefits, especially the application of promoting antitumor immune defense. However, immune-related adverse events (irAEs) caused by immune checkpoint inhibitors have received increasing attention, which largely limits their use. We report the first case of new acute mastitis caused by anti-PD1 inhibitors due to lung adenocarcinoma. A 65-year-old female patient came to our hospital for treatment with cough and shortness of breath for one month. Chest CT showed that the malignant tumor in the lower lobe of the right lung with pleural effusion had metastasized to many places, and then pleural effusion was taken for pathological examination. Pathological examination indicated that the pleural fluid originated from lung adenocarcinoma. Subsequently, the patient received platinum-containing dual-agent chemotherapy (carboplatin and pemetrexed disodium) combined with immunotherapy (camrelizumab). During treatment, the patient developed known adverse events and unreported acute mastitis. After stopping camrelizumab, the patient’s mastitis gradually improved. Our case shows that acute mastitis might be a new adverse event after the use of camrelizumab. Since this new adverse event has not been reported, we hope that oncology medical workers can obtain insight from our case and use it as a reference for the identification and management of irAEs.

Ultrasonic multimodality imaging features and the classification value of nonpuerperal mastitis

OBJECTIVE

To explore the value of ultrasonic multimodality imaging for characterizing nonpuerperal mastitis (NPM) lesions and feasibility of distinguishing different subtypes.

METHODS

Thirty-eight NPM lesions were assessed using conventional ultrasonography (US), strain elastography (SE), and contrast-enhanced ultrasound (CEUS). The lesions were confirmed pathologically and classified as granulomatous lobular mastitis (GLM), plasma cell mastitis (PCM), or nonspecific mastitis (NSM). Furthermore, diagnostic indicators were evaluated. The diagnostic performances of the modalities were compared using the area under the receiver operating characteristic curve (AUC).

RESULTS

The overall morphological features on US differed significantly between the GLM and PCM groups (p = 0.002). Lesion size (≤10 mm) (p = 0.003) and mean SE score (p = 0.001) differed significantly between the PCM and NSM groups. The frequent NPM characteristic on CEUS was hyperenhancement with (or without) increased lesion size; intergroup differences were not significant. Breast Imaging Reporting and Data System > 3 was considered to indicate malignancy; accordingly, the accuracy of US alone, US with CEUS, and US with SE was 10.5%, 21.1%, and 65.8%, respectively. Moreover, the AUC for US with SE for classifying GLM and PCM was 0.616.

CONCLUSION

CEUS cannot accurately classify NPM subtypes, while US and SE are valuable for classification.

Current Understanding and Management of Plasma Cell Mastitis: Can We Benefit from What We Know?

BACKGROUND

Plasma cell mastitis (PCM), also known as mammary duct ectasia, is a chronic nonbacterial breast inflammation characterized by duct expansion and plasma cell infiltration. The severe and intense clinical manifestations profoundly affect the quality of life of female patients. Although the pathological process of PCM is known to include four stages (duct dilatation, inflammation, abscess and fistula), there is still lack of imaging techniques and serum markers with high specificity in clinical practice. Due to recurrent acute attacks and the prolonged healing process of the disease, most patients choose to accept mastectomy.

SUMMARY

We searched for studies, reports and reviews referring to PCM in the past 20 years; more than half of the results were related to animal studies, and little attention has been paid to human beings, which may explain the frequent misdiagnosis of PCM as breast cancer and the limited treatment options. This review focuses on the current diagnostic methods and markers for PCM and hierarchically discusses the typical clinical features, etiological causes and relevant molecular mechanisms of PCM.

KEY MESSAGES

We herein highlight the urgent need to develop more specific and sensitive biomarkers in the clinical laboratory. It will help to establish a standardized flowchart for the diagnosis and treatment of PCM in order to improve recovery for female patients.

Pruritic breast mass with palpable lymph nodes in a male patient: a case report

This paper presents a case study of a 78-year-old male patient who presented with exacerbated skin redness and edema on the left chest wall, especially on the left breast, and who had been suffering from associated pruritus for 6 months. The patient also presented with enlarged ipsilateral axillary lymph nodes that were suspected to be carcinomas after a preliminary ultrasound and enhanced computerized tomography (CT) examination were performed. To examine these symptoms, an ultrasound-guided core biopsy and a chronic inflammatory test were also performed. The results of the excision biopsy and the immunohistochemistry test of the left breast and ipsilateral lymph node revealed no signs of cancer in this patient. Finally, combined with his medical history, the laboratory tests and pathology results, the patient was diagnosed with plasma cell mastitis (PCM) after another suspicious lesion (e.g., inflammatory breast cancer, etc.) was excluded. PCM is a kind of benign lesion of the breast with an unclear etiology. It usually affects non-pregnant and non-lactational females, who display clinical symptoms that are often similar to those of inflammatory breast cancer (IBC), the main manifestations were erythema and edema on the chest wall. To date, there is no standardized clinical treatment strategy or management approach for PCM.

Mastitis and More: A Pictorial Review of the Red, Swollen, and Painful Breast

Clinically, acute mastitis presents as a red, swollen, and painful breast. Targeted ultrasound can be performed to evaluate the extent of infection and for an underlying abscess. Noncomplicated mastitis or a small fluid collection may respond to oral antibiotics without further intervention, but a larger or more complex abscess may require single or serial percutaneous aspiration. Breast infections, particularly those complicated by an abscess, can have a prolonged clinical course, and close follow-up is required. Since the clinical presentation and imaging features of acute infectious mastitis can overlap with other etiologies, such as inflammatory breast cancer and idiopathic granulomatous mastitis, a percutaneous biopsy may be indicated to accurately diagnose patients.

Clumped vs non-clumped internal enhancement patterns in linear non-mass enhancement on breast MRI

OBJECTIVE

To compare positive predictive values (PPVs) of clumped vs non-clumped (homogenous and heterogeneous) internal enhancement on MRI detected linear non-mass enhancement (NME) on MRI-guided vacuum-assisted breast biopsy (MRI-VABB).

METHODS

With IRB (Institutional Review Board) approval, we retrospectively reviewed 598 lesions undergoing MRI-VABB from January 2015 to April 2018 that showed linear NME. We reviewed the electronic medical records for MRI-VABB pathology, any subsequent surgery and clinical follow-up. The X² test was performed for univariate analysis.

RESULTS

There were 120/598 (20%) linear NME MRI-VABB lesions with clumped (52/120, 43%) vs non-clumped (68/120, 57%) internal enhancement, average size 1.8 cm (range 0.6-7.6 cm). On MRI-VABB, cancer was identified in 22/120 (18%) lesions, ductal carcinoma in situ (DCIS) was found in 18/22 (82%) and invasive cancer in 4 (18%). 3/31 (10%) high-risk lesions upgraded to DCIS at surgery, for a total of 25/120 (21%) malignancies. Malignancy was found in 12/52 (23%) clumped lesions and in 13/68 (19%) of non-clumped lesions that showed heterogeneous (5/13, 38%) or homogenous (8/13, 62%) internal enhancement. The PPV of linear NME with clumped internal enhancement (23.1%) was not significantly different from the PPV of non-clumped linear NME (19.1%) (p = 0.597). The PPV of linear NME lesions <1 cm (33.3%) was not significantly different from the PPV of lesions ≥1 cm (18.6%) (p = 0.157).

CONCLUSIONS

Linear NME showed malignancy in 21% of our series. Linear NME with clumped or non-clumped internal enhancement patterns, regardless of lesion size, might need to undergo MRI-VABB in appropriate populations.

ADVANCES IN KNOWLEDGE

Evaluation of linear NME lesions on breast MRI focuses especially on internal enhancement pattern.

Differential diagnosis of plasma cell mastitis and invasive ductal carcinoma using multiparametric MRI

Background

Evaluate the potential of multiparametric magnetic resonance imaging (MRI) for the differential diagnosis of plasma cell mastitis (PCM) and invasive ductal carcinoma (IDC).

Methods

A total of 465 female patients, including 197 PCM (42.4%) and 268 IDC (57.6%), were examined using breast MRI scanning using routine sequences, dynamic contrast-enhanced MRI (DCE-MRI), diffusion-weighted imaging (DWI) and MR spectroscopy (MRS). The MRI features of PCM and IDC lesions were analyzed and compared to the histological results.

Results

Compared to IDC, the PCM lesions were more frequent in the subareolar regions, hyperintense on T2WI (P<0.01) and showed an initial signal increase ≤90%, a persistent and plateau pattern of time-intensity curves, non-mass enhancement, multiple rim enhancements, central hyperintensity on DWI, a higher ADC value, and total choline (tCho) peak negative and tCho peak integral <29.95 AU (P<0.01). The following breast-associated findings were also observed frequently in PCM: Ipsilateral breast enlargement, nipple retraction, skin thickening, peripheral edema and axillary lymphadenopathy. However, no significant difference was observed between the two groups for the shape, border and adjacent vessel signs of the lesion.

Conclusions

Some of the MRI features of PCM and IDC lesions were different. An integrated analysis of these multiparametric MRI features can thus assist in the differential diagnosis of PCM and IDC lesions.

Combining ultrasonography and mammography to improve diagnostic accuracy of plasma cell mastitis

OBJECTIVE

To evaluate the diagnostic value of ultrasonography and mammography for plasma cell mastitis.

METHODS

The ultrasonographic and mammographic images of 111 women with histopathologically confirmed plasma cell mastitis were retrospectively analyzed. The diagnostic accuracy of the two imaging methods was compared.

RESULTS

Ultrasonography identified 91 out of 111 (82.0%) patients with plasma cell mastitis, while the other twenty (18.0%) patients were misdiagnosed. Mammography identified 83 (74.8%) out of 111 patients with plasma cell mastitis. Nineteen (17.1%) patients were misdiagnosed. There was no significant difference between the diagnostic accuracy of using two imaging tests (P = 0.127). Mammography clouds identified 11 out of 20 patients who were not diagnosed by ultrasonography. Meanwhile, 19 of the 28 cases misdiagnosed with mammography were correctly identified by ultrasonography. Overall, 91.9% (102/111) of the patients were identified by the combination of ultrasonography and mammography, which yielded statistically significant higher accuracy than using each single test only (P < 0.05).

CONCLUSIONS

In diagnosis of plasma cell mastitis, high-frequency ultrasonography and mammography should be combined to improve the diagnostic accuracy.

Differentiation between Clinically Noninflammatory Granulomatous Lobular Mastitis and Noncalcified Ductal Carcinoma in situ Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging

<b><i>Introduction:</i></b> Challenges in differentiation between clinically noninflammatory granulomatous lobular mastitis (GLM) and noncalcified ductal carcinoma in situ (DCIS) remain. <b><i>Objective:</i></b> To identify the dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) characteristics contributing to their differential diagnosis. <b><i>Methods:</i></b> A total of 33 clinically noninflammatory GLM and 36 noncalcified DCIS were retrospectively analyzed in the study. Internal enhancement of a nonmass enhancement (NME) lesion was divided into clustered enhanced ring (absence/presence), and clustered enhanced ring (presence) was further classified as small and large ring based on the optimal cutoff value. The 5th Breast Imaging and Data System MRI descriptors were used for assessing the other DCE-MRI characteristics. Multivariate analysis including variables with significant differences in univariate analyses was conducted to identify the independent predictors. The discriminative abilities of different predictors and their combination were compared by area under the receiver-operating characteristic curves (AUCs). <b><i>Results:</i></b> An NME lesion was seen more commonly in clinically noninflammatory GLM than in noncalcified DCIS (<i>p</i> = 0.003). DCE-MRI characteristics with significant differences in univariate analyses included NME size, clustered enhanced ring (absence/presence), ring size, initial increase and kinetic characteristics for the differentiation between these two entities presenting as NME lesion. Clustered enhanced ring (presence) was further classified as small (≤7 mm) or large ring (&#x3e;7 mm). Multivariate analysis revealed that internal enhancement and initial increase were identified as significant independent predictors, and the AUC of their combination achieved the highest value of 0.867 (95% CI, 0.748–0.943). <b><i>Conclusions:</i></b> An NME lesion with a large ring is more highly suggestive of clinically noninflammatory GLM.

Sonographic features of inflammatory conditions of the breast

Inflammatory conditions of the breast can be a diagnostic challenge, and ultrasound is a proven valuable tool in this setting. In acute infective conditions, ultrasound is often a superior tool to mammography due to the impracticality of applying compression to the breast and the increased parenchymal density of these often younger patients. Although infective processes comprise the majority of inflammatory conditions in the breast, not infrequently other various disease processes can masquerade as infections. In particular, inflammatory breast cancer can be easily misdiagnosed as an infective process and sonography can play an important role in expediting the correct diagnosis. Furthermore, aspiration, drainage and biopsy are frequently required in managing breast inflammation and breast disease generally, and ultrasound is the most practical imaging modality facilitating such interventions. This article provides a review of the ultrasound characteristics of some of the more frequently encountered inflammatory disorders of the breast which span a spectrum of acute to chronic conditions. The various conditions in this report are described in terms of their specific sonographic imaging features as well as pathogenesis, common clinical presentations, and aspects of management are outlined where appropriate.

Is negative-pressure wound therapy beneficial in modern-day breast surgery?

Negative-pressure wound therapy (NPWT) is used to treat many different types of wounds, but there is still a lack of large studies describing its effectiveness in breast surgery. Enhanced recovery, reduction of complications, and good scar quality might be improved by the application of NPWT. Existing data show that vacuumassisted closure (VAC) application after expander-based breast reconstruction may be beneficial because of decreasing overall complications in comparison with standard wound treatment. There are few cases in which the use of negative pressure resulted in healing of complicated breast wounds after implant insertion - most breasts achieved healing, wherein duration of NPWT ranged from seven to 21 days. The use of NPWT leads to a decrease of seroma formation (from 70% to 15%), the mean percutaneous aspirated volume (from 193 ml to 26 ml) and the numbers of percutaneous aspirations (from three to one) in latissimus dorsi flap reconstruction. Furthermore, a prospective, within-patient, randomised study with 200 participants showed that treating closed incisional wounds after reduction mammoplasty with a VAC system resulted in a decrease of overall complications and protected against wound dehiscence. In the literature, there are cases showing that NPWT may be useful for the successful treatment of chronic and non-healing wounds, included non-puerperal mastitis and surgical sites affected by radiation therapy due to breast cancer. There is still a need for evidence confirming the effectiveness of NPWT in breast surgery because of the deficiency of large prospective studies that compare NPWT with standard treatment.

Imaging Features of Inflammatory Breast Disorders: A Pictorial Essay

Inflammatory breast disorders include a wide array of underlying causes, ranging from common benign infection, non-infectious inflammation and inflammation resulting from underlying breast malignancy. Because it is at times difficult to distinguish mastitis and breast cancer based on clinical features, awareness of detailed imaging features may be helpful for better management of inflammatory breast disorders. Therefore, this pictorial essay intends to demonstrate radiologic findings of a variety of inflammatory breast disorders, using selected cases with mammography, ultrasound and magnetic resonance images.

Two-dimensional shear wave elastography for differential diagnosis between mastitis and breast malignancy

OBJECTIVE

To determine the diagnostic performance of conventional ultrasound (US) and two-dimensional shear wave elastography (2D SWE) in the differential diagnosis between mastitis and breast malignancy.

METHODS

Between January 2016 and March 2017, 105 patients with 105 pathologically proven breast lesions were enrolled. All the lesions were subject to conventional US and 2D SWE examinations. In 2D SWE, the qualitative parameter of stiff rim sign and quantitative parameter of maximal shear wave velocity (SWV) were obtained. The diagnosis performances of US and combination of US and 2D SWE were evaluated, including sensitivity, specificity and the area under the receiver operating characteristic curve (AUROC). The AUROC of US and the combined method were also evaluated in subgroups with different diameters.

RESULTS

Pathologically, 26 breast lesions were confirmed to be mastitis and 79 were malignant. The cut-off value for maximal SWV was 6.75 m/sec. The AUROC of stiff rim sign and maximal SWV were 0.701 (95% CI: 0.587-0.815) and 0.753 (95% CI: 0.659-0.832) respectively. Compared with US, the specificity and AUROC of the combined method increased significantly (specificity: 11.5% vs. 96.1%, AUROC: 0.520 vs. 0.752; both P < 0.05).

CONCLUSIONS

The combination of US and 2D SWE improved the diagnostic performance in the differential diagnosis between mastitis and breast malignancy in comparison with the conventional US alone.

Subareolar breast abscess in male patients: a report of two patients with a literature review

Background

Subareolar breast abscess (SBA) is a rare infectious disease of the breast in male patients.

Case presentation

Herein, we report two male patients with SBA. Patient 1 was initially diagnosed with a malignant tumor based on imaging findings; ultrasonography revealed a hypoechoic mass with blood flow. Patient 2 was diagnosed with inflammatory changes to his nipple; ultrasonography findings supported the diagnosis with an irregular hypoechoic mass with blood flow. Both patients received a cytological or histological biopsy preoperatively, which showed an abscess without malignant cells.

Conclusion

These cases serve as an important reminder to consider complete resection of the tumor including the responsible mammary duct (tumor and duct resection (TDR)) for curative therapy of SBA.

Diffusion-weighted imaging in relation to morphology on dynamic contrast enhancement MRI: the diagnostic value of characterizing non-puerperal mastitis

Objectives

To demonstrate the value of diffusion-weighted imaging (DWI) in the characterisation of mastitis lesions.

Methods

Sixty-one non-puerperal patients with pathologically confirmed single benign mastitis lesions underwent preoperative examinations with conventional MRI and axial DWI. Patients were categorised into three groups: (1) periductal mastitis (PDM), (2) granulomatous lobular mastitis (GLM), and (3) infectious abscess (IAB). Apparent diffusion coefficient (ADC) values of each lesion were recorded. A one-way ANOVA with logistic analysis was performed to compare ADC values and other parameters. Discriminative abilities of DWI modalities were compared using the area under the receiver operating characteristic curve (AUC). P < 0.05 was considered statistically significant.

Results

ADC values differed significantly among the three groups (P = 0.003) as well as between PDM and IAB and between PDM and GLM. The distribution of non-mass enhancement on dynamic contrast-enhanced (DCE) MRI differed significantly among the three groups (P = 0.03) but not between any two groups specifically. There were no differences in lesion location, patient age, T₂WI or DWI signal intensity, enhancement type, non-mass internal enhancement, or mass enhancement characteristics among the three groups.

Conclusions

ADC values and the distribution of non-mass enhancement are valuable in classifying mastitis subtypes.

Key points

• Mastitis subtypes exhibit different characteristics on DWI and DCE MRI.

• ADC values are helpful in isolating PDM from other mastitis lesions.

• Distribution of non-mass enhancement also has value in comparing mastitis subtypes.

Radiologic-Pathologic Correlation for Benign Results After MRI-Guided Breast Biopsy

OBJECTIVE

The majority of MRI-guided breast biopsies yield benign pathology. The purpose of this article is to provide a comprehensive overview of benign pathologic entities commonly encountered at MRI-guided breast biopsy.

CONCLUSION

Proper radiologic-pathologic correlation is an integral component of MRI-guided breast biopsy. Familiarity with the spectrum of MRI findings and key histopathologic features of common benign entities will enhance the radiologist's confidence in determining concordance and lead to improved patient management recommendations.

[Diagnosis and treatment of inflammatory diseases of the mammary ducts]

AIM

The analysis and popularization of the own experience of ultrasonic diagnostics and minimal invasive interventions for inflammatory diseases of the mammary ducts.

PATIENTS AND METHODS

249 women were observed: 182 (73.1%) cases of periductal mastitis and 67 (26.9%) cases of purulent galactophoritis. Patients with purulent galactophoritis were divided into 2 groups (main and control). The main group consisted of 50 patients after minimal invasive interventions, control - 17 women after traditional surgery.

RESULTS

The main US signs of periductal mastitis and purulent galactophoritis were detected. Purulent galactophoritis is associated with the diameter of mammary duct less than 4 mm, ductal content flotation and stream-effect (coloring of dilated duct in Doppler mode). It was proposed the method of US-assisted mini-invasive retrograde drainage of mammary ducts with aspiration of purulent content through the natural orifice in the nipple. This method doesn't demand hospital stay, reduces duration of treatment by 14 days and doesn't cause the cosmetic defects in comparison with traditional surgical approach.

CONCLUSION

Inflammatory diseases of the mammary ducts are represented by the different nosological forms - periductal mastitis (73.1%) and purulent galactophoritis (26.9%). In view of typical ultrasonic picture in patients with purulent galactophoritis US-assisted mini-invasive retrograde drainage of mammary ducts with aspiration of purulent content through the natural orifice in the nipple is advisable. This method has significant advantages in comparison with traditional surgery and may be recommended for widespread clinical use.

Sonographic Elastography of Mastitis

Sonographic elastography has been shown to be a useful imaging modality in characterizing breast lesions as benign or malignant. However, in preliminary research, mastitis has given false-positive findings on both strain and shear wave elastography. In this article, we review the findings in mastitis with and without abscess formation on both strain and shear wave elastography. The elastographic findings in all cases were suggestive of a malignancy according to published thresholds. In cases of mastitis with abscess formation, there is a characteristic appearance, with a central very soft area (abscess cavity) and a very stiff outer rim (edema and inflammation). This appearance should raise the suspicion of mastitis with abscess formation, since these findings are rare in breast cancers.

Nodular fasciitis in the axillary tail of the breast

Nodular fasciitis is a benign proliferation of myofibroblasts which presents clinically as a rapidly growing mass with nonspecific features on imaging and high cellular activity on histopathology. Nodular fasciitis can be mistaken for malignant fibrous lesions such as soft tissue sarcoma or breast carcinoma when located within breast tissue. This presents a problem for appropriate treatment planning as the natural history of nodular fasciitis is spontaneous regression. We present the mammographic, sonographic, computed tomography, and histopathologic characteristics of nodular fasciitis in a 68 year female initially presenting with a rapidly enlarging right axillary mass.