Multimodality imaging of benign and malignant male breast disease

Male Breast Cancer: Imaging Considerations for Diagnosis and Surveillance

Male breast cancer accounts for less than 1% of all breast cancer cases. The important risk factors for the development of male breast cancer are family history, genetic mutations, obesity, liver disease, alcoholism, exogenous estrogen administration, and radiation exposure to the chest area. Despite its rarity, numerous studies have investigated the data on imaging considerations (mammogram, ultrasound, and magnetic resonance imaging (MRI)), but have addressed only certain aspects of male breast cancer. A comprehensive approach on the imaging characteristics, timing of imaging, prognostication based on imaging characteristics, and follow-up strategies in male breast cancer are still lacking. The purpose of this review article was to provide a comprehensive overview of the imaging findings, optimal timing to obtain imaging, and the appropriate follow-up strategies in male breast cancer survivors. This article also describes how imaging modalities can aid in determining prognosis. By addressing this knowledge gap, the article provides valuable insights for clinicians managing this uncommon yet clinically significant disease.

The ins and outs of male breast and anterior chest wall lesions from childhood to adulthood

Physiological and pathological processes arising from the breast and anterior chest wall may share similar clinical presentations because of the small volume of male breasts. Therefore, imaging is frequently required to localise and characterise the lesion and guide biopsy when radiological findings are equivocal or suspicious. Mammography or digital breast tomosynthesis (DBT) and ultrasound are the mainstays of breast imaging work-up. Other imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI) and positron-emission tomography (PET) can sometimes augment the investigation and aid treatment planning. This article reviews the key imaging features of a wide spectrum of benign and malignant conditions that involve the male breast and anterior chest wall across various age groups. Familiarisation with the salient radiological findings is essential for reaching an accurate diagnosis and optimising management.

Outcomes of male patients attending the symptomatic breast unit: adherence to local and national imaging guidelines and effectiveness of clinical examination and imaging in detecting male breast cancer

AIM

To review outcomes of male patients attending the breast unit, evaluate effectiveness of imaging and examination in detecting breast cancer and review adherence to guidelines for male breast imaging.

MATERIALS AND METHODS

A retrospective review was undertaken of male patients attending Cambridge Breast Unit from 1 January 2015 to 31 December 2019. Patient electronic records and imaging were reviewed to establish demographics, clinical findings, imaging, biopsy, and pathology outcomes.

RESULTS

Of 1,362 male patients attending the breast unit, 1,028 (75%) had imaging performed. Biopsy was performed in 41 men (3%), with 14 cancers diagnosed (1%). Clinical examination showed 42.7% sensitivity, 99.6% specificity, 54.6% positive predictive value (PPV) and 99.4% negative predictive value (NPV) for detection of cancer. Mammogram demonstrated 84.6% sensitivity, 99.4% specificity, 69.8% PPV, and 99.8% NPV for detection of malignancy. Ultrasound demonstrated 78.6% sensitivity, 98.9% specificity, 73.3% PPV and 99.2% NPV for detection of cancer. Forty-one percent of patients <40 years and 51% < 50 years were imaged, who according to local and Royal College of Radiologists (RCR) guidelines did not require imaging based on age and clinical score.

CONCLUSION

Male patients account for a small proportion of referrals to the breast unit but generate significant workload. Imaging protocols, incorporating clinical score and age cut-off at 40 years remains robust for detecting malignancy. Clinician awareness of the imaging protocol, and close liaison with radiologists is essential to minimise additional radiology workload.

An Approach Based on Mammographic Imaging and Radiomics for Distinguishing Male Benign and Malignant Lesions: A Preliminary Study

Purpose

To develop and validate an imaging-radiomics model for the diagnosis of male benign and malignant breast lesions.

Methods

Ninety male patients who underwent preoperative mammography from January 2011 to December 2018 were enrolled in this study (63 in the training cohort and 27 in the validation cohort). The region of interest was segmented into a mediolateral oblique view, and 104 radiomics features were extracted. The minimum redundancy and maximum relevance (mRMR) and the least absolute shrinkage and selection operator (LASSO) methods were used to exclude radiomics features to establish the radiomics score (rad-score). Mammographic features were evaluated by two radiologists. Univariate logistic regression was used to select for imaging features, and multivariate logistic regression was used to construct an imaging model. An imaging-radiomics model was eventually established, and a nomogram was developed based on the imaging-radiomics model. Area under the curve (AUC) and decision curve analysis (DCA) were applied to assess the clinical value.

Results

The AUC based on the imaging model in the validation cohort was 0.760, the sensitivity was 0.750, and the specificity was 0.727. The AUC, sensitivity and specificity based on the radiomics in the validation cohort were 0.820, 0.750, and 0.867, respectively. The imaging-radiomics model was better than the imaging and radiomics models; the AUC, sensitivity, and specificity of the imaging-radiomics model in the validation cohort were 0.870, 0.824, and 0.900, respectively.

Conclusion

The imaging-radiomics model created by the imaging characteristics and radiomics features exhibited a favorable discriminatory ability for male breast cancer.

Differential diagnosis of benign and malignant male breast lesions in mammography

PURPOSE

To investigate the mammographic characteristics in discriminating benign and malignant male breast lesions.

METHODS

Male patients with breast lesions detected by preoperative mammography were enrolled in this study from Jan 2011 to Dec 2018. All lesions were confirmed by biopsy and classified into benign group or malignant group. Imaging features included lesions location, lesion type, lesion density, lesion eccentricity, accompanying signs(calcification, nipple retraction, thickened skin and enlarged lymph nodes) were recorded and analysed by statistical methods. The AUC was calculated to assess their diagnostic performance in distinguishing benign and malignant lesions. This model was further validated by 0.632 bootstrap.

RESULTS

A total of 93 men(median age: 60, range 32-81 years) were enrolled, 43 patients in the benign group and 50 patients in the malignant group. In the univariate logistic analysis, age, lesion location, lesion type, lesion density, lesion eccentricity, calcification, nipple retraction and skin thickening were significantly different (p < 0.05). When the lesion showed a mass in mammography, those with a circumscribed margin were likely malignant (p < 0.05). In the multivariate logistic analysis, non-retro-areola lesions (OR: 6.900, 95 % CI: 1.413∼33.691, p < 0.05), eccentric lesions (OR: 14.566, 95 % CI: 2.800∼75.777, p < 0.05), high-density lesions (OR: 11.052, 95 % CI: 2.235∼54.666, p < 0.05), calcification (OR: 12.715 95 % CI: 1.316∼122.848, p < 0.05) and nipple retraction (OR: 24.681, 95 % CI: 2.853∼213.542 p < 0.05) were associated with breast cancer. Those variables were used to build logistic model and the AUC of the imaging model was 0.904. The imaging model was verified by 0.632 bootstrap resampling, and the AUC after 0.632 bootstrap was 0.892.

CONCLUSION

Mammographic characteristics could contribute to distinguishing malignant and benign male breast lesions, and the imaging model showed excellent diagnostic performance, which may help to guide clinical decision-making.

Incidental Gynecomastia on Thoracic Computed Tomography in Clinical Practice: Characteristics, Radiologic Features, and Correlation With Possible Causes in South Korean Men

Gynecomastia is a common incidental finding on thoracic computed tomography (CT). This study aimed to retrospectively determine the prevalence, imaging characteristics, and possible causes of incidental gynecomastia on thoracic CT. Records of male patients who underwent thoracic CT in 2015 were reviewed. The size and morphologic types (nodular, dendritic, and diffuse) were recorded for patients with breast glandular tissue larger than 1 cm, and the cutoff value of gynecomastia was defined as 2 cm. Additionally, the possible causes of gynecomastia obtained by reviewing patients' charts were recorded. CT-depicted gynecomastia was identified in 12.7% (650 of 5,501) of patients. The median size of the breast glandular tissue was 2.5 cm (interquartile range 2.2-3.1), and 36.8% of patients (239 of 650) had unilateral gynecomastia. The age distribution provided a bimodal pattern with two peaks in the age groups from 20 to 29 years old and greater than 70 years old. Chronic liver disease (CLD; p < .001), all stages of chronic kidney disease (CKD; p < .001), and medications (p = .002) were significantly associated with gynecomastia. Gynecomastia did not correlate with body mass index (p = .962). The size of breast glandular tissue was identified to be correlated with the morphologic type of breast tissue and the severity of CLD or CKD. The prevalence of incidental gynecomastia seen on thoracic CT was 12.7%. CT-depicted gynecomastia is not associated with obesity but with CLD, CKD, and medications. When gynecomastia is detected on CT, further evaluations and management might be required for patients with a treatable cause.

Is gynecomastia related to the disease characteristics and prognosis in testicular germ cell tumor patients?

PURPOSE

We aimed to assess the relationship between gynecomastia and tumor markers, histologic subtypes, and prognosis in patients with testicular germ cell tumors.

METHODS

This study included 73 testicular germ cell cancer patients with pretreatment chest, abdomen and pelvis computed tomography (CT) scans and tumor markers (β-human chorionic gonadotropin [β-hCG], lactate dehydrogenase [LDH], α-fetoprotein [AFP]). The volumetric analysis of the breast glandular tissue, the presence of gynecomastia and metastatic disease were determined using CT scans. Patients were classified according to the International Germ Cell Cancer Collaborative Group (IGCCCG) prognostic classification. The association between gynecomastia, breast glandular tissue volume, tumor markers, metastatic disease, and disease prognosis were evaluated.

RESULTS

Thirty-four of the patients (46.6%) had gynecomastia. A breast volume cutoff value of 0.78 cm3 to diagnose gynecomastia led to 85% sensitivity and 95% specificity. Serum β-hCG level correlated with the breast glandular tissue volume weakly (r=0.242, P = 0.039). Gynecomastia was more common in patients with elevated β-hCG levels (P = 0.047), and was not associated with pulmonary, nonpulmonary distant, or nodal metastases (P = 0.378, P = 0.884, P = 0.333, respectively). No significant association was found between the disease prognosis and gynecomastia (P = 0.556).

CONCLUSION

Gynecomastia was common among testicular germ cell cancer patients with elevated β-hCG. However, it was not associated with metastatic disease and prognosis.

Male Breast: Clinical and Imaging Evaluations of Benign and Malignant Entities with Histologic Correlation

Breast cancer is an uncommon disease in men. As a result, the diagnosis may not initially be considered. Understanding the common benign and malignant entities affecting the male breast is critical for timely and accurate diagnosis in the primary care setting. Most patients present with a palpable breast mass or pain. The usual etiology is gynecomastia, the most common breast condition in males, but breast cancer must always be excluded through careful imaging evaluation when physical examination findings are suspicious or inconclusive. Imaging of the male breast generally relies on mammography and ultrasound, with mammography employed as the initial imaging modality of choice and ultrasound when a mass is detected or suspected. Here we describe the normal male breast anatomy and present an evaluation algorithm for the male patient with breast signs or symptoms. The most common benign and malignant entities are described.

Incremental Role of Mammography in the Evaluation of Gynecomastia in Men Who Have Undergone Chest CT

OBJECTIVE

The purpose of this study was to determine whether additional breast imaging is clinically valuable in the evaluation of patients with gynecomastia incidentally observed on CT of the chest.

MATERIALS AND METHODS

In a retrospective analysis, 62 men were identified who had a mammographic diagnosis of gynecomastia and had also undergone CT within 8 months (median, 2 months). We compared the imaging findings of both modalities and correlated them with the clinical outcome.

RESULTS

Gynecomastia was statistically significantly larger on mammograms than on CT images; however, there was a high level of concordance in morphologic features and distribution of gynecomastia between mammography and CT. In only one case was gynecomastia evident on mammographic but not CT images, owing to cachexia. Two of the 62 men had ductal carcinoma, which was obscured by gynecomastia. Both of these patients had symptoms suggesting malignancy.

CONCLUSION

The appearance of gynecomastia on CT scans and mammograms was highly correlated. Mammography performed within 8 months of CT is unlikely to reveal cancer unless there is a suspicious clinical finding or a breast mass eccentric to the nipple. Men with clinical symptoms of gynecomastia do not need additional imaging with mammography to confirm the diagnosis if they have undergone recent cross-sectional imaging.