Gynecomastia is a benign enlargement of the male breast resulting from a proliferation of the glandular component of the breast (see the image). Gynecomastia is defined clinically by the presence of a rubbery or firm mass extending concentrically from the nipples. Although the condition is usually bilateral, it can be unilateral. The condition known as pseudogynecomastia, or lipomastia, is characterized by fat deposition without glandular proliferation.
Reassure patients with physiologic gynecomastia regarding the benign nature of their condition, and inform them that most cases spontaneously resolve.