The cardiac silhouette was preserved with obtuse lung margins suggesting a mediastinal mass over cardiomegaly or a lung parenchymal etiology.  Benign causes in this age group include thymoma, hernia, abscess, or many others. Malignant causes could include lymphoma, or germ cell tumors among many others.  A lateral view aided in the differential due to the presence of an air-fluid level which favored a gastrointestinal etiology.  

The patient subsequently received a CT interrogation confirming the presence of stomach and transverse colon contents herniating through a widened esophageal hiatus centered at T10.  The patient was referred to a tertiary pediatric surgery facility and underwent a laparoscopic hiatus hernia repair with mesh, fundoplication, and gastrostomy for decompression and enteral access.  The patient was discharged 6 days postoperatively into the community.