A non-seminomatous germ cell tumor arising from the testis and characterized by the presence of various tissues which correspond to the different germinal layers (ENDODERM; MESODERM, and ECTODERM). Mature teratomas consist of adult tissues whereas immature teratomas consist of fetal tissues. The prognosis for pediatric patients is generally good, however, teratomas may metastasize in adolescent and adult patients. May be hereditary or caused by somatic mutations. OMIM: 273300
