Delayed-onset pancreatitis secondary to migration of a fully covered self-expanding metal biliary stent: a case report.

Fully covered self-expanding metal stents (FCSEMS) are widely used for malignant biliary obstruction but may cause complications, including pancreatitis. Most cases occur shortly after placement, while delayed presentations are uncommon. We report a 74-year-old woman with metastatic adenocarcinoma and prior FCSEMS placement who presented months later with severe epigastric pain, nausea, vomiting, and markedly elevated lipase. Imaging showed an indwelling biliary stent without pancreatic abnormalities. Endoscopic retrograde cholangiopancreatography demonstrated migration of the FCSEMS into the ampulla with purulent biliary drainage. The migrated stent was removed and replaced, resulting in rapid symptom resolution. This case highlights FCSEMS migration as a rare cause of delayed pancreatitis due to mechanical obstruction of the pancreatic duct. Clinicians should consider this diagnosis in patients presenting with pancreatitis months after biliary stent placement, as prompt endoscopic intervention can lead to favorable outcomes.