Intraductal papillary neoplasms of bile duct. A distinct entity like its counterpart in pancreas

Impact of Tumor Location on Postoperative Outcome of Intraductal Papillary Neoplasm of the Bile Duct

BACKGROUND

The concept of intraductal papillary neoplasm of the bile duct (IPNB) has been proposed to be the biliary equivalent of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. While the classification of IPMNs is based on their location of duct involvement, such classification has not been fully evaluated for IPNBs. The aim of this study is to investigate the value of IPNB classification based on its location.

METHODS

A total of 306 consecutive patients who underwent surgical resection with a diagnosis of bile duct tumor were enrolled. Among these patients, 21 were diagnosed as having IPNB. The IPNBs were classified into two groups as follows: extrahepatic IPNB, which located in the distal or perihilar bile duct, and intrahepatic IPNB, which located more peripherally than the hilar bile duct. The clinicopathological features of the two groups were then compared.

RESULTS

Extrahepatic IPNB tended to show more invasive characteristics than intrahepatic IPNB (presence of invasive component: 40.0 vs. 9.1%, p = 0.084). Moreover, patients with extrahepatic IPNB showed significantly poorer relapse-free survival (RFS) than those with intrahepatic IPNB [5-year RFS rate (%): 81.8 vs. 16.2, p = 0.014].

CONCLUSION

Patients with intrahepatic IPNB show more favorable pathological characteristics and postoperative survival outcomes than those with extrahepatic IPNB.

Haemostatic radiation therapy for a bleeding intraductal papillary neoplasm of the biliary tree

Haemostatic radiation was effectively used as a novel rescue therapy in a 60-year-old man who presented with recurrent melaena refractory to all conventional medical and surgical measures. He needed multiple transfusions and was diagnosed to be bleeding from an intraductal papillary biliary neoplasm which was not amenable to surgical resection in view of the background liver disease. He received conventional radiation therapy (RT) of a dose of 3 Gy per fraction for 3 consecutive days after which he stabilised. After cessation of the RT, he did not require transfusion for the next 2 months. His quality of life improved and it gave us time to evaluate for other definitive measures.

CT imaging comparison between intraductal papillary neoplasms of the bile duct and papillary cholangiocarcinomas

OBJECTIVES

To identify imaging features that assist in discriminating intraductal papillary neoplasms of the bile duct (IPNBs) from papillary cholangiocarcinomas (PCCs).

METHODS

This study was approved by the institutional review board. Using the recently proposed histological diagnostic criteria for biliary papillary neoplasms, IPNBs and PCCs were selected from 537 biliary neoplasms consecutively resected in a 12.5-year period. Clinical and imaging features were compared between the two groups.

RESULTS

The histology review identified 19 IPNBs and 48 PCCs, representing an estimated prevalence of IPNBs among biliary neoplasms of 4%. Approximately one half of IPNBs were incidentally found on imaging conducted for other purposes. In terms of tumor location, 15/19 IPNBs (79%) developed in intrahepatic bile ducts, and 41/48 PCCs (85%) in the distal bile duct. Cystic appearance was highly suggestive for IPNBs (p < 0.001). Using these two parameters, 78% of papillary bile duct neoplasms could be classified into IPNBs or PCCs. Other imaging findings favoring IPNBs included frond-like mural nodule, downstream bile duct dilatation, and the lack of abnormal enhancement in the adjacent bile duct. Interestingly, two patients with non-invasive or microinvasive IPNB had undergone abdominal imaging studies > 3 years before, and a retrospective review of the previous images identified small nodular or cystic lesions, suggesting a less progressive nature of IPNBs than currently thought.

CONCLUSIONS

Imaging findings useful for discriminating IPNBs from PCCs appear to be tumor location, shape of tumor, appearance of mural nodules, duct dilatation at unaffected duct, and abnormal enhancement of the adjacent bile duct.

KEY POINTS

• Intrahepatic location and cystic dilatation of the affected bile duct are the strong discriminators between IPNBs and PCCs. • The shape of the mural nodule and appearance of the neighboring bile duct are helpful for distinguishing IPNBs and PCCs. • The less aggressive behavior of IPNBs compared with PCCs may facilitate less invasive management in patients with IPNB.

Spread of Intraductal Papillary Neoplasm Arising from the Cystic Duct of the Biliary Tree

Intraductal papillary neoplasm of the bile duct (IPNB) is a variant type of the bile duct carcinoma characterized by intraductal growth. IPNB is also recognized as a precursor of invasive carcinoma. We describe herein an extremely rare case of IPNB arising from the cystic duct. A 68-year-old man was admitted to our hospital for investigation of epigastralgia and abnormal levels of biliary tract enzyme. Computed tomography and magnetic resonance imaging showed a mass lesion spreading from the cystic duct to the upper-middle bile duct. Endoscopic retrograde cholangiography demonstrated diffuse duct dilation with a grossly visible intraductal mass and amorphous blobs, suggesting the presence of mucobilia or scattered tumors. We performed extrahepatic bile duct resection with lymphadenectomy. Macroscopically, a friable papillary tumor originated from the cystic duct grows intraluminally into the bile duct. Pathologically, the tumor was found to be intramucosal adenocarcinoma spreading to the whole extrahepatic bile duct, which was compatible with IPNB. We should discuss the features and progression processes of IPNB through this precious case.

Intraductal papillary neoplasms of the bile duct

Intraductal papillary neoplasm of the bile duct (IPNB) is a rare variant of bile duct tumors characterized by papillary growth within the bile duct lumen and is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm of the pancreas. IPNBs display a spectrum of premalignant lesion towards invasive cholangiocarcinoma. The most common radiologic findings for IPNB are bile duct dilatation and intraductal masses. The major treatment of IPNB is surgical resection. Ultrasonography, computed tomography, magnetic resonance image, and cholangiography are usually performed to assess tumor location and extension. Cholangioscopy can confirm the histology and assess the extent of the tumor including superficial spreading along the biliary epithelium. However, pathologic diagnosis by preoperative biopsy cannot always reflect the maximum degree of atypia, because IPNBs are often composed of varying degrees of cytoarchitectural atypia. IPNBs are microscopically classified into four epithelial subtypes, such as pancreatobiliary, intestinal, gastric, and oncocytic types. Most cases of IPNB are IPN with high-grade intraepithelial neoplasia or with an associated invasive carcinoma. The histologic types of invasive lesions are either tubular adenocarcinoma or mucinous carcinoma. Although several authors have investigated molecular genetic changes during the development and progression of IPNB, these are still poorly characterized and controversial.

A huge intraductal papillary mucinous carcinoma of the bile duct treated by right trisectionectomy with caudate lobectomy

Background

Because intraductal papillary mucinous neoplasm of the bile duct (IPMN-B) is believed to show a better clinical course than non-papillary biliary neoplasms, it is important to make a precise diagnosis and to perform complete surgical resection.

Case presentation

We herein report a case of malignant IPMN-B treated by right trisectionectomy with caudate lobectomy and extrahepatic bile duct resection. Radiologic images showed marked dilatation of the left medial sectional bile duct (B4) resulting in a bulky cystic mass with multiple internal papillary projections. Duodenal endoscopic examination demonstrated very patulous ampullary orifice with mucin expulsion and endoscopic retrograde cholangiogram confirmed marked cystic dilatation of B4 with luminal filling defects. These findings suggested IPMN-B with malignancy potential. The functional volume of the left lateral section was estimated to be 45%. A planned extensive surgery was successfully performed. The remnant bile ducts were also dilated but had no macroscopic intraluminal tumorous lesion. The histopathological examination yielded the diagnosis of mucin-producing oncocytic intraductal papillary carcinoma of the bile duct with poorly differentiated carcinomas showing neuroendocrine differentiation. The tumor was 14.0 × 13.0 cm-sized and revealed no stromal invasiveness. Resection margins of the proximal bile duct and hepatic parenchyma were free of tumor cell. The patient showed no postoperative complication and was discharged on 10^th postoperative date. He has been regularly followed at outpatient department with no evidence of recurrence.

Conclusion

Considering a favorable prognosis of IPMN-B compared to non-papillary biliary neoplasms, this tumor can be a good indication for aggressive surgical resection regardless of its tumor size.

Intraductal papillary neoplasm of the bile duct associated with Clonorchis sinensis infection

Intraductal papillary neoplasm of bile duct (IPNB) is one of the precursor lesions of cholangiocarcinoma. Although hepatolithiasis has been extensively studied in its association with IPNBs, there had been no comprehensive study of IPNBs with Clonorchis sinensis infection. Twelve IPNBs were selected from 20 surgically resected cholangiocarcinomas, positive for C. sinensis tests (60%) and compared with eight IPNBs, selected from 51 resected cholangiocarcinomas, negative for C. sinensis tests (16%), by histologic and immunohistochemical studies of mucin core proteins and cytokeratin panels. The predominant immuno-phenotype of IPNB cases with Clonorchiasis was pancreatobiliary type (MUC1+/MUC2-/CDX2-; 9/12 cases), while that of IPNB cases with negative for C. sinensis was intestinal type (MUC1-/MUC2+/CDX2+; 6/8; p = 0.04). The prevalence of IPNBs was higher when patients with cholangiocarcinoma had Clonorchiasis. IPNBs with Clonorchiasis tended to have a more pancreatobiliary phenotype, which suggests IPNBs with Clonorchiasis may have a different tumorigenesis pathway from IPNBs with other etiologies.