Gynecomastia is breast enlargement in men due to excessive growth of breast tissue under and around the areola (nipple). Also called man boobs in pop culture.
Pseudogynecomastia is breast enlargement in men caused by excessive subcutaneous fat in the pectoral area. It is also called lipomastia or adipomastia.
Reduction Mammoplasty is the medical term used for surgical removal of breast tissue. It is the official medical term for gynecomastia surgery.
Mixed gynecomastia is breast enlargement as a result of breast tissue and pectoral fat. 99% of cases of breast enlargement in men is a combination of breast tissue and chest fat.