AbstractBackgroundChronic pancreatitis is the most common etiology of pancreaticopleural fistula (PPF) in children, and underlying genetic variations are now widely known, accounting for most chronic pediatric pancreatitis.Case reportWe describe a case of previously undetected chronic pancreatitis and PPF with aSPINK1variation in a 10-year-old Thai boy who presented with massive left pleural effusion. Magnetic resonance cholangiopancreatography (MRCP) revealed disruption of the pancreatic duct, which was communicating with a large pancreatic pseudocyst with mediastinal extension. The patient subsequently underwent endoscopic intervention with improved clinical symptoms. We also reviewed the imaging findings of 12 other reported cases of pediatric PPF.ConclusionsMassive pleural effusion due to PPF can be an atypical manifestation in children with chronic pancreatitis. MRCP is the preferable imaging study for PPF due to the production of highly detailed images of pancreatic duct disruptions and anatomy, and the imaging is helpful to guide for appropriate treatment. Tests for genetic variation are also recommended in a child with chronic pancreatitis.