EUS‐FNA diagnosis of pancreatic tophaceous gout: Two rare cases

Abstract

AbstractWe report two patients with pancreatic tophaceous gout diagnosed by endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) of presumed cystic mass lesions. The first case involved a patient who had a recent episode of acute pancreatitis 6 months prior, with subsequent imaging concerning for a pseudocyst or mass lesion. The second case involved a patient with epigastric pain associated with a pancreatic head cystic mass and an erroneous original diagnosis of a mucinous pancreatic neoplasm on EUS‐FNA. Diff‐Quik stained direct smears on fresh material obtained from EUS‐FNA of the lesions showed chalky debris with needle shaped negatively birefringent crystals consistent with gout. For the first case, the chalky material was not present on the H&E stained paraffin embedded formalin fixed cellblock slides. The importance of inclusion of cytologic specimen preparations to examine monosodium urate crystals is emphasized.