Confocal laser endomicroscopy in diagnosing indeterminate biliary strictures and pancreatic lesions − a prospective pilot study

Abstract

An accurate histopathological diagnosis of indeterminate biliary strictures and pancreatic lesions is challenging because of insufficient quali-ty of tissue specimen taken during ERCP (brush cytology), cholangioscopy (biopsies) or endosonography (EUS, FNAB). Confocal laser endomicroscopy (CLE) allows virtual histopathological diagnosis with the potential to either replace or increase the diagnostic yield of standard histopathological diagnosis in patients presenting with biliary strictures and pancreatic lesions. The aims of our prospective pilot study were to: 1. Assess the diagnostic yield of standard histopathology compared to CLE in patients referred for cholangioscopy or for EUS of the pancreas; 2. Evaluate the cost of CLE in these indications. CLE was performed (during cholangioscopy or EUS), followed by standard tissue sampling. CLE-based diagnosis was compared with standard histopathology/cytology. CLE probe was introduced through the working channel of the cholangioscope or through the FNAB needle. Atotal of 23 patients were enrolled (12 women, mean age 61 years); 13 patients underwent cholangioscopy and 10 patients underwent EUS. Cholangioscopy: CLE diagnosed correctly all 4 malignant strictures (histology 2 of them only as 2 patients had insufficient quality of the tissue specimen). Agreement between standard histopathology and CLE was achieved in 85%. EUS: All 3 cases of pancreatic cancer were correctly diagnosed by both CLE and FNAB. All remaining (premalignant and benign) lesions were also correctly diagnosed by both methods. The cost of CLE examination is higher compared to FNAB but comparable with tissue sampling during digital cholangioscopy. CLE demonstrated sufficient diagnostic accuracy in patients with indeterminate biliary strictures or pancreatic lesions and, therefore, might improve diagnostic accuracy or even replace standard histopathology in these indications.