Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of pancreatic cysts obtains cyst fluid for cytologic and biochemical analysis, which may determine whether the cyst is mucinous and malignant, contributing to patient management. Despite this added value, EUS-FNA remains controversial in the preoperative assessment of pancreatic cysts. The objective of this study was to assess the utility of EUS-FNA in a cohort of small pancreatic cysts that were benign on imaging studies.
All pancreatic cysts that underwent initial EUS-FNA in 2006 and 2007 were retrospectively analyzed. Ninety-two patients with pancreatic cysts met the inclusion criteria. Patients who had high-risk or worrisome features on imaging studies were excluded. Cytology, histology, and cyst fluid analysis data were collected. The main outcome measurements were radiologic and clinical follow-up as well as cytopathologic and histologic results.
EUS-FNA supported a diagnosis of a mucinous cyst in 38 of 92 patients (41%) by carcinoembryonic antigen (CEA) measurement and/or cytology. Cytology demonstrated an absence of high-grade atypia (HGA) in 89 of 92 patients (97%). The mean follow-up was 4.4 years (range, 0-7.7 years), during which 6 cysts were surgically resected and 16 cysts were resampled by at least 1 subsequent EUS-FNA. The overall negative predictive value of cytologic examination for HGA was 99%.
EUS-FNA is a screening test that contributes to a triple-negative test for pancreatic cysts--no high-risk stigmata, no worrisome features, and no HGA on cytology--providing a negative predictive value of 99% for conservative management.