Source:http://linkedlifedata.com/resource/umls/id/C0238451
NCI: A non-seminomatous germ cell tumor arising from the testis. It is characterized by the presence of various tissues which correspond to the different germinal layers (endoderm, mesoderm, and ectoderm). According to the level of differentiation of the tissues which comprise the tumor, testicular teratomas are classified as mature or immature. Mature teratomas are composed of well differentiated, adult-type tissues. Immature teratomas are composed of immature, fetal type-tissues. Testicular teratomas in children follow a benign clinical course whereas in postpubertal patients may metastasize to other anatomic sites.