Gynecomastia is a condition of excessively large breasts in a male. Most commonly it is associated with over weight teen boys. In addition male breasts can occur in teens who smoke massive amounts of Marijuana. THC (tetra-hydra-cannibinol) the active ingrediant in maryjane/reefer/spliff/loud ( depending on your generation) blocks the Testosterone receptors resulting in feminization. Most young adult Gynecomastic happens for unknown reasons. Gynecomastia in middle aged and elderly men is associated with erectile dysfunction, potbellys and a shrinking scrotum. In these cases the aging process lowers lean body mass and Testosterone levels. Common condition and medications can also be associated with the development of breast tissue in men. Prostate cancer treatment is just one well established cause.
There are several treatment options all of which are surgical. Currently the most elegant procedure is the scarless mastectomy pictured here. This is done using LASER liposculpture which removes fat and breast tissue and tightens the skin.