Intraductal biopsies in indeterminate biliary stricture: Evaluation of histopathological criteria in fluoroscopy- vs. cholangioscopy guided technique

Abstract Background Differentiating malignancy from benign disease in indeterminate biliary stricture by imaging modalities is limited. Definite diagnosis relies on histopathological diagnosis. Aims To assess accuracy of histopathological diagnosis of fluoroscopy-guided vs. cholangioscopy-directed intraductal biopsies in indeterminate biliary stricture. Methods All patients with indeterminate biliary stricture and fluoroscopically (n = 68) or cholangioscopy-directed (working channel 2 mm, n = 38) biopsies were included. Histopathological results of biopsies were classified into inflammatory lesion (class 1), dysplasia/intraepithelial neoplasia (class 2) and malignancy (class 3) and results as well as macroscopic diagnosis were compared with final diagnosis. Results Sensitivity and specificity of fluoroscopy-guided vs. cholangioscopy-directed biopsies were 22.9% and 100% vs. 25.0% and 100% for class 1 + 2 vs. class 3 lesions, respectively. Sensitivity for class 1 vs. class 2 + 3 lesions was 45.7% ( p = 0.044) vs. 58.3% ( p = 0.214) for fluoroscopy-guided vs. cholangioscopy-directed biopsies, respectively, while specificity was 100% in both. There was no difference in size of the obtained sample (p = 0.992). True positive diagnosis rate increased with the number of biopsies taken (p = 0.028). Conclusion Fluoroscopy-guided and cholangioscopy-directed intraductal biopsies are equally limited in establishing the diagnosis of malignancy in indeterminate biliary stricture. Categorising dysplasia or intraepithelial neoplasia as malignancy increases sensitivity without decrease in specificity. By taking more biopsies, diagnostic yield is increased.