Routine Cyst Fluid Cytology Is Not Indicated in the Evaluation of Pancreatic Cystic Lesions

Background: The work-up of cystic lesions of the pancreas often involves endoscopic ultrasound (EUS) with fine needle aspiration (FNA). In addition to CEA and amylase measurement, fluid is routinely sent for cytologic examination. We evaluated the utility of cytologic findings in clinical decision-making. Materials and Methods: Records of patients who underwent EUS-guided pancreatic cyst aspiration were reviewed. Findings from axial imaging and EUS were compared to cyst fluid cytology as well as fluid amylase and CEA. All results were then compared to final diagnosis, determined by clinical analysis for those patients not resected, and surgical pathology report for those who underwent resection. Results: A total of 167 patients were reviewed. Of 48 patients with suspicious findings on imaging, cytology yielded diagnostic information in 89.6 % of cases (43 patients). However, in the 119 patients where no suspicious components were revealed on imaging, fluid cytology yielded no significant diagnostic results in any case. In all cases where mucin was noted on cytologic review, thick fluid was also seen at the time of aspiration. Discussion: In our cohort of patients with cystic pancreatic lesions, cytologic analysis of pancreatic cyst fluid yielded no diagnostic benefit over radiologic findings alone. In such cases where fluid is to be aspirated, specimens that would otherwise be sent for cytologic evaluation would be better served for other purposes, such as molecular analysis or banking for future research.