Detection of an intraductal component of a pancreatic ductal adenocarcinoma using a novel ultrathin pancreatoscope

Pancreatic juice cytology (PJC) is sometimes used to diagnose early pancreatic ductal adenocarcinoma (PDAC), which typically presents as a main pancreatic duct (MPD) stricture without a detectable pancreatic mass on imaging.[ 1​ ] In patients with intraductal papillary mucinous neoplasms (IPMNs), peroral pancreatoscopy (POPS) can be used to evaluate MPD involvement and obtain biopsy specimens in addition to PJC.[ 2​ ] However, POPS using a conventional slim scope is generally not suitable for evaluating suspected PDAC because the MPD is usually not dilated near the papilla. Herein, we report the feasibility of a novel ultrathin pancreatoscope for the visualization of the MPD in suspected PDAC without a detectable pancreatic mass. A 68-year-old woman was referred for MPD dilatation in the pancreatic body and tail detected on ultrasonography. Using contrast-enhanced computed tomography (CECT) and magnetic resonance cholangiopancreatography, a MPD stricture was revealed in the pancreatic head with upstream ductal dilatation ( Figs. [ 1 ] and [ 2 ]). No pancreatic mass was detected using CECT, magnetic resonance imaging, and endoscopic ultrasound (EUS). Therefore, POPS using an ultrathin pancreatoscope (DRES Slim Scope; Japan Lifeline, Tokyo, Japan) was performed ([ Video 1​ ]). Fig. 1 A computed tomographic image showing the dilated main pancreatic duct (arrow) without evidence of pancreatic mass. Fig. 2 Magnetic resonance cholangiopancreatography showing a short-segment stricture of the MPD in the pancreatic head with upstream MPD dilatation. Video 1 Peroral pancreatoscopy using a novel ultrathin pancreatoscope. VIDEO URI: . Download Video Endoscopic retrograde pancreatography demonstrated an abrupt cutoff of the MPD in the pancreatic head ([ Fig. 3a ]). POPS revealed a fish-egg-like mucosa surrounding the MPD stricture ([ Fig. 3b ]). Transpapillary biopsy from the cutoff confirmed adenocarcinoma. While awaiting pancreatoduodenectomy (PD), scheduled 2 months later, EUS was again performed because of elevated CA19-9 levels, and a 10-mm hypoechoic mass was observed in the pancreatic head. After neoadjuvant chemotherapy with gemcitabine plus S-1, the patient underwent PD. Pathology confirmed moderately differentiated tubular adenocarcinoma (pT2N0M0, Stage IB). Fig. 3 ( a ) In an endoscopic retrograde cholangiopancreatography image, an abrupt cutoff of the MPD was observed at the pancreatic head. ( b ) Using the novel ultrathin pancreatoscope, pancreatic ductal mucosa at the site of the pancreatic duct stricture had a fish-egg-like appearance. Although a SpyGlass DS system (Boston Scientific Corporation, Natick, Massachusetts, USA), which has an outer diameter of 3.6 mm, is commonly used for evaluating IPMNs with a dilated MPD, a novel ultrathin pancreatoscope with an outer diameter of 2.6 mm (reduced to 2.2 mm when combined with a CytoMax II Double Lumen Biliary Cytology Brush [Cook Medical Japan, Tokyo, Japan] as a catheter and a Fielder 18 guidewire [Asahi Intecc Co., Ltd, Seto, Aichi, Japan]) may represent a promising modality for visualizing malignant MPD strictures even without ductal dilatation near the papilla. Endoscopy_UCTN_Code_CCL_1AZ Publication History Received: 24 June 2026 Accepted after revision: 13 July 2026 Article published online: 29 July 2026 © 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/). Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany