A case of pancreatic arteriovenous malformation diagnosed after the onset of abdominal symptoms.

Pancreatic arteriovenous malformation (P-AVM) is an extremely rare vascular anomaly characterized by abnormal connections between arteries and veins bypassing the capillary network. Less than 200 cases have been reported worldwide, and standardized treatment guidelines have not yet been established. A 72-year-old man presented with abdominal distension, diarrhea, and appetite loss. Contrast-enhanced abdominal computed tomography revealed a 5 cm mass in the pancreatic tail with multiple feeding and draining vessels, a portosystemic shunt, and moderate ascites, suggesting a P-AVM. Endoscopic ultrasonography revealed a hypoechoic area in the pancreatic tail measuring 50 mm in diameter. Esophagogastroduodenoscopy revealed F2-type esophageal varices. Based on imaging findings and clinical history, the patient was diagnosed with P-AVM, and Osler-Weber-Rendu disease was excluded. Initial treatment with transarterial embolization was attempted, but proved insufficient due to high blood flow and multiple feeders. Surgical resection via distal pancreatectomy was subsequently performed to alleviate portal hypertension and resolve abdominal symptoms, although significant intraoperative bleeding occurred. This case highlights the diagnostic and therapeutic challenges of P-AVMs, particularly in high-flow lesions with complex vascular anatomy. Surgical resection remains the definitive treatment for symptomatic P-AVM and effectively resolves the associated complications. The insights gained from this case may contribute to the clinical management of this rare condition.