RT Journal Article SR Electronic A1 Rizzo, Toni T1 Pericardial Teratoma: An Uncommon Masquerader JF MD Conference Express YR 2012 FD SAGE Publications VO 12 IS 12 SP 28 OP 29 DO 10.1177/155989771212014 UL http://mdc.sagepub.com/content/12/12/28.abstract AB Teratomas are benign germ-cell tumors that occur in infants through young adults. They contain cell types from at least 2 of 3 primitive germ cell layers. Ectodermal elements often predominate (hair, skin, sweat gland, or tooth-like structures), as well as mesodermal (fat, cartilage, smooth muscle, bone) or endodermal (respiratory and intestinal epithelium) elements. Pericardial teratomas most commonly arise in the anterior superior mediastinum. These tumors usually are diagnosed in infants and children <10 months of age at a rate of 5 to 6 per 10,000 children. They are exceptionally rare in adults.