NCI Definition: A non-seminomatous germ cell tumor characterized by the presence of various tissues which correspond to the different germinal layers (endoderm, mesoderm, and ectoderm). It occurs in the testis, ovary, and extragonadal sites including central nervous system, mediastinum, lung, and stomach. According to the level of differentiation of the tissues which comprise the tumor, 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. Mature ovarian teratomas without a fetal-type component have an excellent outcome. The prognosis of immature ovarian teratomas is related to the grade and stage of the tumor. 
Teratomas most frequently harbor alterations in TP53, PIK3CA, KMT2D, TET1, and PTEN .
TP53 Mutation, PIK3CA Mutation, TP53 c.217-c.1178 Missense, TP53 Missense, and TP53 Exon 5 Mutation are the most common alterations in teratoma .
There is 1 clinical trial for teratoma, of which 1 is open and 0 are completed or closed. Of the trial that contains teratoma as an inclusion criterion, 1 is no phase specified (1 open).
2. The AACR Project GENIE Consortium. AACR Project GENIE: powering precision medicine through an international consortium. Cancer Discovery. 2017;7(8):818-831. Dataset Version 8. This dataset does not represent the totality of the genetic landscape; see paper for more information.