Unusual presentation of tension pneumoperitoneum during endoscopic submucosal dissection of early gastric tumor

Tension pneumoperitoneum is a well-known but rare complication of upper gastrointestinal endoscopy. It is defined as the massive accumulation of air in the peritoneal cavity, which results in a sudden increase in intraabdominal pressure resulting in hemodynamic or ventilatory compromise. The presentation varies from intense abdominal pain and tenderness to imminent collapse.