A case of pancreatic arteriovenous malformation caused acute pancreatitis.

Arteriovenous malformation (AVM) in the pancreas rarely causes acute pancreatitis. However, even when it does cause pancreatitis, the pathogenesis is unclear. A 61-year-old man was admitted to our hospital for acute pancreatitis. The findings of computed abdominal tomography, magnetic resonance imaging, and endoscopic ultrasonography revealed pancreatic AVM and hematoma in the tail of the pancreas. These lesions were suspected to be associated with pancreatitis. Although endoscopic retrograde pancreatography could not confirm hemosuccus pancreaticus, distal pancreatectomy was performed because of repeated pancreatitis. The histopathological findings of the resected specimen revealed rupture of the AVM vessels into the main pancreatic ducts. Finally, we considered that intermittent bleeding due to AVM rupture and hematoma formation in the main pancreatic duct caused the repeated pancreatitis.