Biliary papillomatosis

Percutaneous transhepatic cholangioscopy: does its role still exist?

Percutaneous transhepatic cholangioscopy (PTCS) is the most widely used modality for diagnosis and treatment of biliary disease. Although many other novel technologies have been developed based on recent advances in endoscopy, PTCS has its own role. In diagnostics, PTCS is used for evaluation of indeterminate biliary strictures, bile duct tumors, and postoperative biliary strictures that cannot be reached by a peroral approach. In therapeutics, the removal of bile duct stones, dilatation of bile duct strictures including postoperative anastomosis site strictures, and local tumor therapy are indications of PTCS. Especially in a therapeutic role, PTCS has the advantage of maneuverability due to a shorter endoscopic length compared to other cholangioscopic modalities. Hence, PTCS has its own indispensable diagnostic and therapeutic roles.

Advances in research on biliary papillomatosis

Biliary papillomatosis is a rare disease that occurs more commonly in elderly males. The usual presentation of this disease is obstructive jaundice or recurrent cholangitis. Characterized by multiple papillary adenomas involving extensive areas of the biliary tree, biliary papillomatosis has a high recurrence rate and a significant risk of malignant transformation. Here, we will review the pathogenesis, clinical features, diagnosis and therapy of biliary papillmatosis.

Molecular and immunohistochemical analysis of intraductal papillary neoplasms of the biliary tract

Intraductal papillary neoplasms (IPNs) of the biliary tract are uncommon lesions that may be solitary or may spread extensively along the biliary tree. Some biliary IPNs are histologically and radiologically similar to intraductal papillary mucinous tumors (IPMNs) of the pancreas and present a risk for progression to invasive cholangiocarcinoma. Unlike pancreatic IPMNs, little is known about their molecular pathogenesis. We studied 14 biliary IPNs (including 5 cases with associated invasive cholangiocarcinoma) for genetic alterations in the APC/beta-catenin pathway, K-ras oncogene mutations, p53/chromosome 17p alterations, and Dpc4/18q alterations. Immunohistochemistry was performed for beta-catenin, p53, and Dpc4, and microdissected tissue was analyzed using direct DNA sequencing for exon 1 of K-ras and exon 3 of beta-catenin and allelic loss assays on chromosomes 5q, 17p, and 18q. Activating mutations in codon 12 of the K-ras oncogene were present in 4 of 14 (29%) biliary IPNs. Of these 4 cases, 2 patients had associated invasive cholangiocarcinoma, and identical K-ras mutations were present in both the intraductal and invasive components. Allelic loss on chromosome 18q was present in 4 of 13 informative cases (31%); however, no loss of normal Dpc4 expression was detected by immunohistochemistry. Nuclear accumulation of beta-catenin protein was demonstrated in 3 of 12 cases (25%); however, there were no beta-catenin gene mutations, and allelic loss on 5q was present in only 1 of 10 informative cases (10%). Both immunohistochemistry for p53 and 17p allelic loss assays were negative. Biliary IPNs therefore demonstrate a K-ras gene mutation frequency that is lower than that previously reported for pancreatic IPMNs, but similar to that reported for hepatic cholangiocarcinomas. The presence of K-ras mutations in 2 purely intraductal neoplasms, and identical K-ras mutations in 2 cases with both intraductal and invasive components, suggests that these mutations arise early in tumorigenesis. Finally, the frequency of allelic loss on 18q suggests that a locus on 18q is involved in the molecular pathogenesis of biliary IPNs, but this locus is not DPC4.