1345 Pancreatic Pseudocyst Leading to Gastric Outlet Obstruction: A Hard Diagnosis to Swallow

Abstract

INTRODUCTION: Recurrent pancreatitis with pseudocyst can present with gastric outlet obstruction. Endoscopic evaluation should be utilized in certain contexts, especially to exclude more sinister causes of this presentation. CASE DESCRIPTION/METHODS: A 43-year-old woman with a history of alcohol use disorder presented with a gastric outlet obstruction. This was felt secondary to a pancreatic pseudocyst given multiple episodes of recurrent pancreatitis, the last being 1 week prior to her current admission. On presentation, physical exam was significant for ascites and epigastric tenderness. Labs were notable for AST 214 U/L, ALT 99 U/L, alkaline phosphatase 147 U/L, lipase of 203 U/L, and negatives serum alcohol. Notably, Ca 19-9 was elevated to 154 IU/mL during admission 2 weeks prior. Computed tomography chest and abdomen revealed bilateral pleural effusions, pseudocyst, and abdominal ascites. A thoracentesis and paracentesis were performed with cytology for both peritoneal fluid and pleural fluid confirming metastatic adenocarcinoma. Given her refractory symptoms, an esophagogastroduodenoscopy (EGD) was performed which showed an obstructing tumor at the gastric outlet with biopsies revealing poorly differentiated gastric adenocarcinoma. A gastric stent was placed; however, she had continued nausea and vomiting. Repeat EGD showed gastric stent failure and subsequent endoscopic gastrojejunostomy with Axios stent was placed. The patient's functional status declined rapidly as a result of her advanced malignancy and on hospital day 8 she suffered a cardiac arrest, passing shortly after being transitioned to comfort cares. DISCUSSION: The patient's prior history of alcohol use disorder, recurrent pancreatitis, and imaging consistent with pancreatic pseudocyst made this case prone to numerous cognitive errors initially obscuring the etiology of her gastric outlet obstruction and pancreatitis. By reframing the presentation, we were able to question pancreatic pseudocyst as the sole source of the gastric outlet obstruction. Traditionally, Ca 19-9 is associated with pancreatic adenocarcinoma. It also can be elevated in the setting of other gastric malignancies and acute pancreatitis. In pancreatitis, absolute value and trends of Ca 19-9 can help differentiate between pancreatitis and malignancy. The diagnostic uncertainty around this patient's presentation with recurrent pancreatitis, pseudocyst, and gastric outlet obstruction required endoscopic evaluation to ultimately diagnose metastatic gastric adenocarcinoma.