Kanneganti A, et al. - Researchers herein report two cases, of which one is a parasitic omental teratoma likely secondary to auto-amputation of an ovarian teratoma with subsequent omental reimplantation and the other one is an omental immature teratoma probably because of parthenogenetic activation of displaced primordial germ cells. They focused on characterizing extragonadal teratomas (EGTs), via a systematic review. Amongst omental EGTs and Pouch of Douglas and uterosacral ligament EGTs, auto-amputation was deemed the commonest cause, while displaced primordial germ cells likely accounted for 70% of upper abdominal EGTs. Limited characterisation of EGT tumour marker profiles was because only 42.9% of cases reported them but 19.2-25.0% exhibited elevated tumour markers. Torsion, rupture, immature components and potential malignant change of the cell lines, all were revealed as the main risks. Management is largely surgical. Although EGTs are rare, these should be given consideration when assessing pelviabdominal masses with imaging features consistent with teratomas. Confirmation is usually intraoperative. In the presence of good surgeon comfort and a size of about 5 cm, a laparoscopic approach is reasonable.