[A patient with autoimmune pancreatitis complicated by pancreatic pseudocyst that caused colonic perforation-induced gastrointestinal bleeding].

A 62-year-old male patient was referred to our hospital for jaundice and bloody feces. He had hyper-IgG4-emia. Computed tomography (CT) showed diffuse pancreatic enlargement, pancreatic pseudocyst, and hematoma of the splenic flexure of the colon. Magnetic resonance imaging (MRI) showed a fistula in the pancreatic pseudocyst and splenic flexure of the colon. Moreover, lower gastrointestinal endoscopy showed a fistula in the same region. Endoscopic retrograde cholangiopancreatography (ERCP) showed narrowing of the main pancreatic duct and stenosis of the lower bile duct. Following this, the patient was diagnosed with autoimmune pancreatitis-induced pancreatic pseudocyst and colonic perforation-induced gastrointestinal bleeding. The pancreatic pseudocyst and fistula were resolved through steroid treatment.