Imaging in gynecomastia

Gynecomastia (GM) is the benign proliferation of glandular tissue in the male breast. It is a common condition, which may occur physiologically and shows three age peaks during a male's lifespan: infancy, puberty, and senescence. An underlying pathology may be revealed in 45%-50% of adult men with GM, such as aggravating medications, systemic diseases, obesity, endocrinopathies, or malignancy.

To discuss the role of imaging in the evaluation of GM and its contribution to therapeutic decision-making.

The current literature was reviewed through PubMed, Scopus, and CENTRAL electronic databases to identify the best available evidence concerning imaging modalities in patients with GM.

Most male breast lesions can be diagnosed on clinical grounds; however, in certain cases, when physical examination is inconclusive, imaging may be helpful.

The main purpose of evaluating a patient with GM is to establish the diagnosis and differentiate true GM from pseudogynecomastia, exclude breast cancer, and detect the possible cause. GM is seen in mammography as a subareolar opacity and three mammographic patterns of GM are described: nodular, dendritic, and diffuse, corresponding to florid GM of early onset, fibrous persistent GM, and GM due to exogenous estrogen administration, respectively. In ultrasound (US), florid GM is depicted as a disk-shaped, hypoechoic area underlying the areola, whereas echogenicity of the lesions increases as fibrosis develops. Data on the use of MRI in the evaluation of the male breast and GM are still limited. Imaging findings can be classified according to the BIRADS (breast imaging reporting and data system) based on their malignant potential.

Both mammography and US are sensitive and specific to diagnose GM and distinguish it from breast cancer. When clinical findings are suggestive of malignancy or imaging findings are inconclusive, a histological confirmation should be sought.