Recurrent yolk sac tumor following resection of a neonatal immature gastric teratoma.

Gastric teratomas are very rare and usually benign. Only a few cases of gastric teratomas with malignant components have been reported. This report describes recurrence of a yolk sac tumor following resection of a neonatal immature gastric teratoma. Gastric teratoma recurring as a malignant lesion has not been previously reported. Recurrence of immature gastric teratomas should be considered, and a periodic follow-up check with alpha-fetoprotein level should be mandatory.