High Diagnostic Yield of Fine Needle Biopsy for Pancreatic Serous Cystadenomas-A Multicenter Study.

Background: Distinguishing serous cystadenoma (SCA), a benign pancreatic cyst, from potentially malignant mucinous pancreatic cystic lesions carries significant clinical and prognostic implications. While endoscopic ultrasound-guided fine needle aspiration is the standard diagnostic tool, its low diagnostic yield often results in additional workup.

Objective: This study evaluates diagnostic yield of fine needle biopsy (FNB) on lesions suggestive of serous cystadenoma on endoscopic ultrasound (EUS).

Methods: Patients with microcystic EUS appearance were identified database search from 2015 to 2022 and procedure information was obtained through a retrospective chart review from 2 large academic centers. Prior cross sectional imaging diagnosis was also obtained. All microcystic lesions with classic "honeycomb" appearance for SCA a on EUS were targeted for FNB and their pathology evaluated.

Results: Thirty-one patients with suspected SCA who underwent EUS-FNB were included. EUS FNB was successful in obtaining diagnosis in 96.8% of patients. Serous cystadenoma was diagnosed via EUS FNB in 27 of 31 patients (87.1%). Of the remaining 4 patients, there was 1 invasive pancreatic ductal adenocarcinoma, 1 pancreatic neuroendocrine tumor, 1 intraductal papillary mucinous neoplasm, and 1 nondiagnostic sample.

Conclusions: EUS-FNB sampling for histopathology is a safe and accurate diagnostic tool for pancreatic SCA. When microcytic lesions are found on endoscopic ultrasound, our study results suggest that fine needle biopsy for histopathology should be considered as the initial diagnostic evaluation tool given the demonstrated improved diagnostic yield for SCA.