Mature Cystic Teratoma
Microscopically, mature cystic teratomas of the mediastinum resemble those seen in the ovary. Cysts may be lined by stratified squamous epithelium containing sebaceous glands and hair follicles. Other cysts may contain simple cuboidal, flattened, or intestinal type epithelium. Islands of hyaline cartilage (seen here), bone, neural tissue, and pancreatic tissue are frequently seen.