Intraductal papillary neoplasm of the bile duct extending superficially from the intrahepatic to extrahepatic bile duct

Intraductal Papillary Neoplasm of Bile Duct: Updated Clinicopathological Characteristics and Molecular and Genetic Alterations

Intraductal papillary neoplasm of the bile duct (IPNB), a pre-invasive neoplasm of the bile duct, is being established pathologically as a precursor lesion of invasive cholangiocarcinoma (CCA), and at the time of surgical resection, approximately half of IPNBs show stromal invasion (IPNB associated with invasive carcinoma). IPNB can involve any part of the biliary tree. IPNB shows grossly visible, exophytic growth in a dilated bile duct lumen, with histologically villous/papillary neoplastic epithelia with tubular components covering fine fibrovascular stalks. Interestingly, IPNB can be classified into four subtypes (intestinal, gastric, pancreatobiliary and oncocytic), similar to intraductal papillary mucinous neoplasm of the pancreas (IPMN). IPNBs are classified into low-grade and high-grade based on lining epithelial features. The new subclassification of IPNB into types 1 (low-grade dysplasia and high-grade dysplasia with regular architecture) and 2 (high-grade dysplasia with irregular architecture) proposed by the Japan–Korea pathologist group may be useful in the clinical field. The outcome of post-operative IPNBs is more favorable in type 1 than type 2. Recent genetic studies using next-generation sequencing have demonstrated the existence of several groups of mutations of genes: (i) IPNB showing mutations in KRAS, GNAS and RNF43 belonged to type 1, particularly the intestinal subtype, similar to the mutation patterns of IPMN; (ii) IPNB showing mutations in CTNNB1 and lacking mutations in KRAS, GNAS and RNF43 belonged to the pancreatobiliary subtype but differed from IPMN. IPNB showing mutation of TP53, SMAD4 and PIK3CA might reflect complicated and other features characterizing type 2. The recent recognition of IPNBs may facilitate further clinical and basic studies of CCA with respect to the pre-invasive and early invasive stages.

A variant of multicystic biliary hamartoma presenting as an intrahepatic cystic neoplasm

A rare case of an intrahepatic multicystic tumor is described. A 26-year-old man visited our hospital because of abdominal discomfort. Contrast-enhanced computed tomography and magnetic resonance cholangiopancreatography revealed a 10 × 7 cm multicystic tumor of the bile duct in the right side of the liver. The gross appearance of the tumor resembled an intraductal papillary neoplasm of the bile duct, and right hepatectomy with regional lymphadenectomy was performed. Histologically, these cystic lesions were composed of variably and irregularly dilated duct structures lined by columnar epithelium resembling bile duct lining. There were no atypical cells and no papillary growth of the epithelial cells. Interestingly, the dilated ducts contained inspissated bile, and the inter-cystic parenchyma contained variable but irregularly distributed and hamartomatous hepatic parenchyma with an abnormal lobular pattern. Though it had atypical features of a hamartoma in some aspects (age, smooth muscle), this case could finally be regarded as a variant of multicystic biliary hamartoma.

Clinicopathological features and prognosis of mucin-producing bile duct tumor and mucinous cystic tumor of the liver: a multi-institutional study by the Japan Biliary Association

BACKGROUND

The aim of this study was to determine the clinicopathological features and surgical outcomes of mucinous cystic neoplasm of the liver (MCN) and mucin-producing intraductal papillary neoplasm of the intrahepatic bile duct (M-IPNB).

METHODS

We performed a multi-institutional, retrospective study of patients with MCN or M-IPNB pathologically defined by the presence or absence of an ovarian-like stroma.

RESULTS

The M-IPNB and MCN were diagnosed in 119 and nine patients, respectively. MCN was observed in female patients, while M-IPNB produced symptoms of cholangitis. M-IPNBs were classed as low or intermediate grade in 53 cases, high grade in 23 and invasive carcinoma in 43. Fifty-one of the M-IPNBs were the pancreatobiliary type (PT), 33 were the intestinal type (IT), 23 were the oncocytic type (OT), and 12 were the gastric type (GT). The 1-, 5- and 10-year survival rates for the 105 patients with M-IPNB were 96%, 84% and 81%, respectively, while the 5-year survival rate for patients with MCN was 100%. OT and GT M-IPNB had better 10-year survival rates than PT and IT M-IPNB.

CONCLUSIONS

Although MCN has different features from M-IPNB, both diseases have a good prognosis after resection. The cellular type of M-IPNB appears to predict outcome.

Intraductal papillary neoplasm of the bile duct in liver cirrhosis with hepatocellular carcinoma

A case of intraductal papillary neoplasm of the bile duct (IPNB) arising in a patient with hepatitis B-related liver cirrhosis with hepatocellular carcinoma (HCC) is reported. A 76-year-old man was admitted to our hospital with recurrent HCC. Laboratory data showed that levels of carcinoembryonic antigen and carbohydrate antigen 19-9 were elevated. He died of progressive hepatic failure. At autopsy, in addition to HCCs, an intraductal papillary proliferation of malignant cholangiocytes with fibrovascular cores was found in the dilated large bile ducts in the left lobe, and this papillary carcinoma was associated with an invasive mucinous carcinoma (invasive IPNB). Interestingly, extensive intraductal spread of the cholangiocarcinoma was found from the reactive bile ductular level to the interlobular bile ducts and septal bile ducts and to the large bile ducts in the left lobe. Neural cell adhesion molecule, a hepatic progenitor cell marker, was detected in IPNB cells. It seems possible in this case that hepatic progenitor cells located in reactive bile ductules in liver cirrhosis may have been responsible for the development of the cholangiocarcinoma and HCC, and that the former could have spread in the intrahepatic bile ducts and eventually formed grossly visible IPNB.

Intraductal papillary growth of liver metastasis originating from colon carcinoma in the bile duct: report of a case

Morphologically, liver metastases from colorectal carcinoma usually form as nodular tumor masses, whereas intraductal papillary growth in the bile duct is rare. A 65-year-old man underwent right hemicolectomy for advanced colon carcinoma, and histology of the primary carcinoma confirmed moderately differentiated adenocarcinoma with subserosal invasion, no vascular infiltration, and no lymph node metastasis. A liver tumor was found in the right paramedian Glisson pedicle and intraductal growth of cholangiocarcinoma was seen on imaging. We performed right hepatectomy and macroscopically, the resected specimen contained a growth in the bile duct lumen similar to cholangiocarcinoma. Histological examination revealed intraductal papillary proliferation of well-differentiated adenocarcinoma without vascular infiltration or lymph node metastasis in the hepatic hilum. Immunohistochemical staining revealed that the tumor cells were negative for cytokeratin-7 and positive for cytokeratin-20. Based on these findings, liver metastasis from colon carcinoma was diagnosed. Liver metastasis from colorectal carcinoma rarely arises as intraductal papillary growth in the bile duct, but the possibility of liver metastases with unusual morphology must be borne in mind for patients with a history of carcinoma in the digestive tract.

A case of intraductal papillary neoplasm of the bile duct with stromal invasion

Intraductal papillary neoplasm of the bile duct (IPNB) represents biliary papillary tumors mainly growing and is considered to be of relatively low-grade malignancy. Here we report a case of IPNB in whom the poorly differentiated component deeply infiltrated the bile duct wall. A 77-year-old male had an invasive carcinoma of the bile duct 3 cm in size. He underwent right hemihepatectomy with combined resection of the extrahepatic bile duct. Papillary growing tumor was observed in the common bile duct and the right posterior Glisson's pedicle was invaded. Histologic finding showed papillary adenocarcinoma in the surface layer superficially extending to the epithelium of the surrounding bile duct. In the subserosal layer, the tumor represented poorly differentiated adenocarcinoma. The tumor was diagnosed as invasive bile duct carcinoma arising from IPNB.