A case of chronic pancreatitis exacerbation associated with pancreatic arteriovenous malformation: a case report and literature review

A 60-year-old man with an unruptured cerebral aneurysm and family history of moyamoya disease was admitted to our hospital with epigastric pain since the previous day. Serum levels of pancreatic enzyme were elevated and abdominal contrast-enhanced computed tomography showed localized enlargement of the pancreatic tail in the arterial phase and revealed numerous areas of fine mesh-like vascular hyperplasia consistent with an enlarged pancreatic tail. We diagnosed pancreatic arteriovenous malformation (P-AVM) with acute pancreatitis. Furthermore, in the pancreatic body, endoscopic ultrasonography showed lobularity (honeycombing type) and hyperechoic foci (non-shadowing), which suggests chronic pancreatitis. Acute management was performed with conservative treatment including administration of replacement fluids and proteolytic enzyme inhibitor. Distal pancreatectomy for P-AVM was performed because P-AVM is associated with acute pancreatitis recurrence, development of portal hypertension, progression of chronic pancreatitis, and refractory duodenal bleeding. Histological findings on the resected specimens revealed the anastomosis of abnormal arteries and veins, which suggested P-AVM. In addition, inflammation accompanied by fat necrosis due to ischemic infarction in the pancreatic tail, which suggested acute pancreatitis, and mild fibrosis in the pancreatic body, which suggested chronic pancreatitis, were shown. Although P-AVM is associated with various complications, symptomatic P-AVM should be considered a chronic and progressive disease.