1393 Calcified Gastroduodenal Artery Aneurysm Presenting as a Pancreatic Mass

Abstract

INTRODUCTION: Gastroduodenal artery (GDA) aneurysm is among the rarest visceral artery aneurysms (VAAs) with an estimated prevalence of 1.5%. Rarely does it present with an outpouching which can sometimes mimic pancreatic malignancy with vastly different outcomes. We report a case of incidental GDA aneurysm which was mimicking a pancreatic mass where EUS was valuable in diagnosis and management. CASE DESCRIPTION/METHODS: A 63-year-old male with a past medical history of heroin and cocaine abuse, presented to the emergency room with shortness of breath and hypoxia. CT angiography revealed acute bilateral pulmonary embolism along with a pancreatic mass. This finding prompted a triple phase CT scan revealing a round 2.8 × 2.6 cm lesion with peripheral thin calcifications identified as a partially thrombosed GDA aneurysm. Additionally, a 2 × 1.5 cm hypodense area was also noticed. However, it was unclear if this was an outpouching from the aneurysm or a separate pancreatic mass. To better delineate the structure, an endoscopic ultrasonography was then performed. The main pancreatic duct and the pancreatic parenchyma were normal with the exception of a calcified abnormality within the GDA. These calcifications were partly contiguous with the GDA aneurysm. No other structural pathology was reported. Pancreatic biopsies were negative for malignancy. Development of the calcified pseudoaneurysm of the GDA was attributed to cocaine abuse. Thereafter, he underwent successful embolization of the aneurysm due to the high risk of bleeding from the aneurysm. He was thereafter discharged with no further complications. DISCUSSION: The most common etiologies of the GDA aneurysms are pancreatitis and atherosclerosis. Unruptured GDAs may present as abdominal pain or obstructive jaundice or remain asymptomatic. Pancreaticoduodenal and GDA aneurysms may manifest with rupturing into stomach, bile or pancreatic ducts in 50-75% of the cases with mortality approaching 50%. Incidentally found GDA aneurysms, as demonstrated in this case, must be treated irrespective of the size and presence or absence of symptoms since the potential of rupture is unrelated to its size. Given the high mortality, it is imperative to diagnose these lesions early. EUS provides valuable information and is useful in diagnosis as is noticed in our case. Therefore, EUS should definitely be considered in cases where diagnosis of GDA aneurysm is considered.