Ex Vivo Endocytoscopic Evaluation of Pancreatobiliary Cancers: A Step Toward Real-time In Vivo Diagnosis.

Abstract

Background/aim: Endocytoscopy (EC) enables real-time diagnosis at extremely high magnification. The aim of the present study was to assess the potential of EC for the prediction of biliary malignancy.

Patients and methods: In total, 23 surgically resected cases with biliary tract cancer (BTCA, n=6), pancreatic head cancer (PCA, n=13), and non-cancerous bile duct lesion (NCBL, n=4) were enrolled in the study. The extrahepatic bile duct mucosa of the resected materials was examined ex vivo using EC.

Results: In cases of BTCA and PCA with bile duct invasion, several independent findings were identified as predictors of cancerous areas using multivariate analysis. These include, extravasation [odds ratio (OR)=15.91; 95% confidence interval (CI)=2.05-123.46], absence of fine network (OR=6.16; 95%CI=1.88-20.19), vascular dilatation (OR=4.87; 95%CI=1.56-15.25) in direct view. Additional predictors observed under methylene blue staining include anisonucleosis (OR=27.77; 95%CI=6.85-112.56), absence of large glands (OR=27.77; 95%CI=6.85-112.56), obscured nuclei (OR=7.63; 95%CI=2.23-26.17), and absence of uniform glands and small/irregular glands (OR=6.18; 95%CI=2.25-16.98). There were no differences in EC findings of non-cancerous areas between BTCA/PCA and NCBL. EC score for predicting the cancerous area (ECS-CA) was established by summing the scores (regression coefficients) of the eight EC findings described above. In the receiver operating characteristic curve analysis, the area under the curve for predicting cancerous areas using the ECS-CA was 0.960 (optimal cut-off ECS-CA, 6.1; sensitivity 91.5%; specificity, 93.6%).

Conclusion: ECS-CA is valuable for assisting in the real-time diagnosis of biliary malignancy in vivo.