Acute Pancreatitis Leading to the Diagnosis of Presymptomatic Crohn's Disease: A Pediatric Case Report.

A 14-year-old boy presented with fever and abdominal pain and was diagnosed with acute pancreatitis based on computed tomography findings. The patient had neither diarrhea nor bloody stool but was diagnosed with microcytic anemia. Endoscopic examination revealed a cobblestone pattern and longitudinal ulcer scars in the jejunum. However, no abnormal findings were observed in the ileum or colon. Endoscopic ultrasound-guided fine-needle aspiration was performed from pancreatic body-tail. Pathological examination revealed no evidence of autoimmune pancreatitis (AIP). It was unclear from pathological examination whether idiopathic pancreatitis had self-limitedly improved or whether it was AIP localized to the pancreatic head. The patient was diagnosed with asymptomatic small-bowel Crohn's disease (CD), which may have been two unrelated events of acute pancreatitis. Acute pancreatitis may precede a diagnosis of inflammatory bowel disease. CD with only jejunal involvement (Montreal classification L4) is extremely rare, and we were able to diagnose it early.