Pancreatic Cyst Cytopathology: Is It Still Worthwhile to Do It?

Abstract

Abstract Objectives Cystic lesions are relatively common in the pancreas, with pseudocysts accounting for 75% to 90% among other etiologies. In contrast to cysts in other organs, cysts in the pancreas are more likely to be neoplastic rather than benign or insignificant. EUS-guided FNA has served as a minimally invasive and fast diagnosis methodology. However, the efficacy of FNA on pancreatic lesions is controversial. Methods A 10-year retrospective study of upper EUS-guided FNA specimens on all cystic lesions in pancreas was conducted at the pathology department of a university hospital. Diagnoses and patient demographics were obtained. The frequency of diagnosis was investigated. When available, the endoscopic findings and CEA levels were obtained for analysis. Results A total of 188 pancreatic cyst FNA cases were collected. Approximately 80% of the specimens were satisfactory for cytology evaluation, and the diagnosis of “negative for dysplasia/malignancy” accounted for the majority of the cases (77.6%). The presence of communication with the pancreatic duct or elevated CEA level (>192 ng/mL) does not change the frequency of negative diagnosis significantly (P = .25). Among the 29 cases with a benign impression on EUS, only 1 case was upgraded to a higher lesion on cytology (3.5%) and this cyst measured >3 cm. Among 86 cysts ≤3 cm, only 1 case was diagnosed as an IPMN and high-grade dysplasia was not identified. All 41 cases with unsatisfactory cytology were due to insufficient cellularity, including 14 cases with an impression of a questionable lesion on EUS. Conclusion In our patient population, EUS-guided FNA of pancreatic cysts does not add significant diagnostic value to EUS findings of benign-appearing pancreatic cysts ≤3 cm and may not be cost-effective overall. Additional molecular testing on cyst fluid obtained by EUS-FNA, especially on cases with insufficient cellularity, may enhance the value of this minimally invasive procedure and improve its diagnostic performance.