15 Breast MRI in Men The term gynecomastia goes back to Galen (129–200 CE). It describes a benign, usually reversible, unilateral or bilateral enlargement of the male breast. Gynecomastia is due to an increase in breast stroma and, to a lesser extent, to ductal proliferation. It is classified into several different categories and may be a normal physiological phenomenon or a pathological finding associated with an underlying disease. Neonatal gynecomastia, pubertal gynecomastia, senescent gynecomastia. These forms of gynecomastia represent physiological conditions due to the status with respect to the appropriate hormones. Breast imaging techniques play no role in the diagnostic work-up. Pathological gynecomastia. Pathological gynecomastia of the adult male develops under the influence of excess estrogen or decreased androgen hormones. In addition, many drugs with an “estrogen-effect” have been found to cause gynecomastia. The following causes deserve special attention: In the T1-weighted precontrast sequence, MR mammography shows a retromamillary area with a low signal-intensity (Fig. 15.1c and Fig. 15.2b). After CM administration this area usually shows no to moderate contrast enhancement (Figs. 15.1a, e, 15.2a, c). The water signal of the parenchymal area is normally somewhat increased (Fig. 15.1b,d). If strong or suspicious contrast enhancement is found, biopsy must be performed to exclude malignancy.
Gynecomastia
Estrogen therapy
Estrogen- or human chorionic gonadotropin-secreting testicular or adrenal tumors
Paraneoplastic syndrome
Cirrhosis of the liver
Anorchism, castration, hypogonadism, Klinefelter syndrome
Hyperthyroidism
Treatment with spironolactone, cimetidine, or verapamil
Marijuana use
MR Mammography
Gynecomastia can occur unilaterally or bilaterally.
