Peroral Pancreatoscopy for Differentiating Main Duct IPMN from Chronic Pancreatitis: A Narrative Review and a Case Series

Main pancreatic duct (MPD) dilatation may occur in both main-duct intraductal papillary mucinous neoplasm (MD-IPMN) and chronic pancreatitis (CP). In selected patients, MRI/MRCP, endoscopic ultrasonography (EUS), and contrast-enhanced EUS may remain inconclusive. Peroral pancreatoscopy (POPS) permits direct ductal inspection and targeted biopsy, but the available evidence is heterogeneous and does not establish diagnostic accuracy or clinical utility in the specific differential diagnosis of MD-IPMN versus CP. We performed a narrative review of POPS for suspected pancreatic duct neoplasia and report a retrospective, descriptive, single-center series of five highly selected patients evaluated between January 2023 and November 2024. The case series is presented only to illustrate a multidisciplinary diagnostic pathway; no estimates of accuracy, sensitivity, specificity, or clinical benefit were calculated. All five patients had MPD dilatation > 10 mm, imaging findings compatible with definite or possible chronic pancreatitis, and persistent concern for MD-IPMN after MRI/MRCP, EUS, and contrast-enhanced EUS. POPS-guided biopsies showed low-grade dysplasia in one patient and high-grade dysplasia in two patients. These three patients underwent surgery, and examination of the resection specimens confirmed the same dysplasia categories identified by POPS-guided biopsy. In the remaining two patients, POPS showed regular-appearing ductal epithelium with focal hyperemia, and targeted biopsies revealed nonspecific inflammatory changes. These patients were managed conservatively without surgery. As definitive surgical histopathology was not available, their final diagnostic status remained unconfirmed. Both patients underwent ongoing planned annual surveillance with MRI or EUS and serum CA 19-9 measurement to identify any morphological or biochemical changes. At the most recent follow-up, approximately 192 days (IQR, 116.5–205.5 days) after POPS, no significant changes had been observed. This small, selected series illustrates how POPS may contribute additional visual and histological information when conventional evaluation is discordant. It cannot demonstrate that POPS prevents missed lesions, excludes IPMN, reduces unnecessary surgery, or improves outcomes. Prospective multicenter studies with predefined referral criteria, blinded interpretation, complete reference standards, and long-term follow-up are needed.