Intraductal Papillary Mucinous Tumor of the Bile Ducts

Abstract

Papillary tumors of the bile ducts are intraductal tumors with numerous minute frondlike papillary projections. Some intraductal papillary tumors of the bile ducts produce a large amount of mucin that disturbs bile flow and causes severe biliary dilatation. In the presence of a tumor of this subgroup, the entire biliary tree is dilated; segmental or lobar bile ducts are dilated disproportionately, and aneurysmal dilatation may occur. Mucin is depicted at cholangiography as multiple elongated or cordlike filling defects, and the tumor is depicted on cross-sectional images as a castlike, polypoid, or fungating mass in the dilated biliary tree. Based on these characteristic imaging features-dilatation, mucin, and tumor-correct diagnosis of intraductal papillary mucinous tumor of the bile ducts may be made.

Characterization of intrahepatic cholangiocarcinoma of the intraductal growth-type and its precursor lesions

“…Generalized dilatation of bile ducts, which is relatively greater in the hepatic segmental ducts, may facilitate making a surgical plan. 13 Serum carcinoembryonic antigen, but not CA19-9, was of some value in differentiating IG-ICC from its precursor lesions.…”

“…Perioperative Management. Work-up for IPNL included liver ultrasonography, computed tomography, endoscopic retrograde cholangiography or percutaneous transhepatic cholangiography, and magnetic resonance cholangiography, 13 in various combinations. During examination by endoscopic retrograde cholangiography or PTC, lumps of mucin were depicited as multiple, elongated linear, ovoid, or amorphous filling defects in dilated bile ducts, and constituted the most characteristic sign of IPNL.…”

MR imaging findings of early bile duct cancer

“…In their study, strictures due to advanced bile duct carcinoma were significantly thicker and longer than benign strictures and frequently showed an indistinct outer margin. Indeed, in our study, the MR features of early bile duct cancers reflect the nature of intraductal papillary tumor, that is, that tumor cells grow and spread superficially along the bile duct mucosa and do not invade deeply into the fibromuscular layer (19). To the contrary, as sclerosing or mass forming type tumors tend to grow in a radial direction and involve perirductal tissue at an early stage, they commonly show a long biliary stricture with wall thickening and an indistinct outer margin, both of which suggest periductal invasion.…”

“…The central, dot-like structures or the vascular structure was identified in eight patients with papillary tumors, but it was not found in nodular tumors. Slender fibrovascular stalks supported by connective tissue from the lamina propria in papillary tumors (19,20), seem to be responsible for the central dot-like or vascular structure seen in the arterial phase. This enhancement pattern may be the characteristic finding of papillary tumors and could provide additional information regarding the nature of the tumor.…”

“…Although endoscopic examinations are generally successful for detecting bile duct obstruction with ductal narrowing, additional CT or MRI would be necessary for preoperative evaluation of tumor staging (22). Although MDCT is widely used for biliary tumor staging, intraductal papillary tumors are easily mistaken for biliary stones and show poor contrast between tumor and bile on CT (19). To the contrary, MR imaging and MRCP may more effectively reveal intraluminal filling defects than CT due to its inherent high soft-tissue contrast.…”