A case of neonatal gastric teratoma complicated with occult gastrointestinal hemorrhage misdiagnosed as lymphangioma

Neonatal gastric teratoma with severe occult gastrointestinal bleeding is extremely rare and hence must be on the list of differential diagnoses of neonatal abdominal mass when a cystic solid mass is found, especially when accompanied by severe anemia without obvious gastrointestinal bleeding. Attention should be paid to the location of the lesion, which is predominantly in the left upper abdomen and has been significantly pushed and displaced by the gastrointestinal tract, and to the imaging characteristics of teratoma such as fat and calcification, which help to exclude other palpable masses encountered during the neonatal period.