This is a mammogram in a male patient that is normal on the left (all fat) and shows gynecomastia on the right (flame-shaped density radiating out from the nipple. The pectoral muscles are larger than in most female patients. It is possible to perform mammography on normal male breasts (like on the left in this patient). Gynecomastia is most often related to drugs (prescription or recreational) or alcoholic liver disease, and if symptoms and history are consistent, no imaging is needed. Genetic disorders such as Klinefelter's syndrome can also produce gynecomastia.