Severe anemia in a 25-day-old infant due to gastric teratoma with focal neuroblastoma

Gastric teratoma is an extremely rare embryonic neoplasm containing tissue from all three germ layers (ectoderm, endoderm, and mesoderm). A 25-day-old infant presented with anemia and a palpable abdominal mass. Computed tomography (CT) scanning showed a solid and cystic multiloculated tumor of mixed echogenicity and calcifications. An encapsulated bleeding tumor localized to the posterior wall of the stomach with extension to a bowel segment was promptly excised. Histology revealed a grade III immature teratoma with small foci of neuroblastoma. To the best of our knowledge, this is the first infant with gastric teratoma containing foci of neuroblastoma causing bleeding and anemia as presentation symptoms at neonatal age.