OPTIMUM NUMBER OF PERCUTANEOUS TRANSHEPATIC CHOLANGIOSCOPY‐GUIDED BIOPSIES FOR HISTOLOGIC DIAGNOSIS OF BILE DUCT CARCINOMA

Background: Percutaneous transhepatic cholangioscopy (PTCS)‐guided biopsy is used for the diagnosis of bile duct carcinoma, but the number of biopsy specimens required for diagnosis is unclear. The aim of this study was to clarify whether multiple PTCS‐guided biopsies are needed for accurate histologic diagnosis. Methods: We examined the relationships between size of the first biopsy specimen, endoscopic, cholangiographic, and pathologic features, and the presence of carcinoma in the first biopsy specimen of the primary lesion in 27 bile duct carcinomas. Results: Twenty‐six of 27 carcinomas (96%) were histologically diagnosed by PTCS‐guided biopsy; 20 (74%) were detected in the first biopsy specimen, six in the second or third biopsy specimen, and one was not detected in four biopsy specimens. Carcinomas with papillogranular mucosa by endoscopy, convex margins by cholangiography, or macroscopic types (except for sclerosing type) were detected on the first biopsy specimen more frequently than were others (15/15 vs 5/12, P <0.001; 13/13 vs 7/14, P <0.01; and 15/16 vs 5/11, P <0.01, respectively). There was no relationship between positivity for carcinoma and size of the first biopsy specimen, vascular dilatation by endoscopy, or histologic type. With the combination of preoperative endoscopy and cholangiography, main lesions with papillogranular mucosa and/or convex margins were proven to be carcinoma on the first biopsy specimen significantly more frequently than were others (17/17 vs 3/10, P <0.0001). Conclusion: If the main lesion contains neither papillogranular mucosa nor a convex margin, multiple PTCS‐guided biopsies should be performed in order to increase the sensitivity for diagnosing bile duct carcinoma.