Gynecomastia. A bothersome but readily treatable problem. Although breast enlargement in boys and men can cause both psychological and physical distress, the disorder is rarely serious and is readily treatable. Several factors can lead to the estrogenic excess that causes growth of breast tissue. Dr Jacobs describes a patient with gynecomastia related to cirrhosis of the liver who responded promptly to a brief course of tamoxifen citrate therapy. 