Postpancreatitis extrapancreatic necrosis mimicking peritoneal carcinomatosis: A pediatric diagnostic pitfall.

A previously healthy 17-year-old female presented with a first episode of acute pancreatitis of unclear etiology. Subsequent imaging revealed extensive post-pancreatitis extrapancreatic necrosis (EXPN) closely mimicking peritoneal carcinomatosis. To our knowledge, pediatric cases of EXPN presenting with carcinomatosis-like imaging findings have rarely been reported. Notably, transient elevation of CA-125 and multifocal long-segment symmetric gastrointestinal wall thickening further increased concern for peritoneal malignancy during the acute phase. Recognition of the evolving imaging manifestations of this benign postinflammatory condition is essential to avoid misdiagnosis and unnecessary invasive investigations, particularly in pediatric patients.