Malignant papillary neoplasms of the intrahepatic bile ducts: CT and histopathologic features

Planned limited resection of the extrahepatic bile duct in a case of intraductal papillary neoplasm of the bile duct based on preoperative examinations

Intraductal papillary neoplasm of the bile duct (IPNB) is defined as a non-invasive malignancy; however, since there are disparities in its histological diagnosis, the operative strategy for typical IPNB has not yet been established. A 69-year-old male was diagnosed with a bile duct mass lesion at the confluence of the cystic duct by ultrasonography without clinical symptoms. Liver functional parameters and tumor markers were within normal ranges. Computed tomography showed an enhanced tumor with no findings of ductal invasion or node metastasis. The tumor was exposed in the hepatic duct lumen and biopsy via SpyGlass DS cholangiography revealed that it was a low-grade papillary lesion, indicating type 1 IPNB. Under preoperative diagnostic modalities, limited resection of the extrahepatic bile duct with D2 lymphadenectomy was planned and R0 resection was achieved. The postoperative histological diagnosis was type 1 IPNB without node metastasis. The postoperative course was uneventful and a good prognosis is expected at this stage. In the field of biliary surgery, although extended resection is generally performed for bile duct carcinomas, satisfactory limited surgical resection is possible for type 1 IPNB with lower malignant behavior.

[Role of magnetic resonance imaging in preoperative assessement of hilar cholangiocarcinoma]

Magnetic resonance cholangiopancreatography is a non-invasive imaging, highly performant in detecting and locating biliary stenosis and in predicting its malignancy. The combination of two and three-dimensional MRI sequences is recommended to assess a biliary obstacle. Cholangiopathies are the main differential diagnosis of cholangiocarcinomas. In addition to bile duct abnormalities beyond the stenosis, the predictive signs of malignancy are: asymmetric irregular luminal narrowing (longer than 3mm and thicker than 13mm), abrupt discontinuation of stenosis, and enhancement superior to that of the adjacent hepatic parenchyma during arterial and portal acquisitions. Diffusion sequences improve the sensitivity of biliary stenosis detection. Moreover, restriction of diffusion is useful for distinguishing malignant from benign stenosis. Combining Magnetic resonance cholangiopancreatography, late LAVA and diffusion sequences improves the sensitivity of detection of a possible biliary extension without significant specificity. MRI with gadolinium chelate injection is efficient in assessing vascular extension of cholangiocarcinomas. However its accuracy remains lower than that of Ct-scan. To assess hepatic, lymphatic and peritoneal extensions of cholangiocarcinomas, it is fundamental to combine diffusion and dynamic MRI sequences.

A huge intraductal papillary neoplasm of the bile duct treated by right trisectionectomy after right portal vein embolization

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 recognized precursor of invasive carcinoma. IPNB was detected incidentally in a 60-year-old woman during check up. Radiologic images revealed a huge cystic mass with papillary projection and markedly dilated bile ducts. Biopsies revealed high-grade IPNB. Cholangioscopy detected a connection between the right posterior bile duct and cyst lumen with epithelial dysplasia of the bile duct. Right posterior sectional duct opened in the left hepatic duct. Consequently, right trisectionectomy and extrahepatic bile duct resection were conducted. Histological studies revealed intraductal papillary neoplasm with high-grade intraepithelial neoplasia (carcinoma in situ). IPNB patients without distant metastases are candidates for surgery and complete resection should be conducted to achieve long-term survival.

Cross-Sectional Imaging of Intrahepatic Cholangiocarcinoma: Development, Growth, Spread, and Prognosis

OBJECTIVE

Intrahepatic cholangiocarcinoma (ICC) is a malignant tumor that arises from the intrahepatic bile ducts. Although the pathologic and imaging features of ICC have been clearly identified, recent updates have addressed the pathologic classification and imaging features of ICC using new imaging techniques. First, a proposed new pathologic ICC subclassification includes perihilar large duct and peripheral small duct ICCs. Second, advanced MR-based imaging features of ICC, such as hepatobiliary phase imaging using hepatocytespecific contrast material and DWI, have recently been described. These imaging features are important when differentiating ICCs from hepatocellular carcinomas. Finally, some imaging features of ICC, such as prominent arterial enhancement or degree of delayed enhancement, exhibit potential as prognostic imaging biomarkers.

CONCLUSION

Comprehensive and updated knowledge of ICC is necessary for accurate diagnosis and could facilitate prediction of clinical outcomes for patients with ICC.

Intrahepatic and extrahepatic intraductal papillary neoplasms of bile duct

There has been an increase in the number of reported cases of biliary neoplasm of the hepatobiliary system characterized by markedly dilated and multifocal papillary epithelial lesions of the bile ducts or cystic biliary lesions with or without mucin secretion, and mucinous lesions or tumors, possibly due to recent advances in radiological diagnosis. This lesion of the bile duct is believed to show a better clinical course than non-papillary biliary neoplasm. Therefore, the early recognition and treatment is important. We report two cases of intrahepatic and extrahepatic intraductal papillary neoplasm of the bile duct that were completely resected.

Hepatic malignancies: Correlation between sonographic findings and pathological features

Ultrasonography (US) findings are inevitably based on pathological features. Knowledge of the pathological features of hepatic malignancies such as hepatocellular carcinoma (HCC), liver metastasis and intrahepatic cholangiocarcinoma is essential for correct US diagnosis and appropriate management. One type of hepatocarcinogenesis is step-wise development from a low-grade dysplastic nodule (DN), high-grade DN, high-grade DN with malignant foci, and well-differentiated HCC, to classical HCC. The intranodular blood supply changes in accordance with this progression. Moreover, the malignant potential tends to change as the macroscopic configuration progresses. Therefore, typical US findings of advanced HCC are a mosaic pattern, septum formation, peripheral sonolucency (halo), lateral shadow produced by fibrotic pseudocapsule, posterior echo enhancement, arterial hypervascularity with dilated intratumoral blood sinusoids, and perinodular daughter nodule formation. Bull's eye appearance is a common presentation of metastases from gastrointestinal (GI) adenocarcinomas, and represents histological findings that show an area of central necrosis surrounded by a zonal area of viable tumor. Thick zonal area reflects the layer of viable cells that are fed by minute tumor vessels. US imaging features of liver metastases from the GI tract are as follows: Bull's eye appearance, multiple masses, irregular tumor border, arterial rim-like enhancement, and hypoenhancement in the late vascular phase. Most intrahepatic cholangiocarcinomas are ductal adenocarcinomas. The bile ducts peripheral to the tumor are usually dilated because of obstruction by tumors. US imaging features of mass-forming cholangiocarcinoma are as follows: peripheral bile duct dilatation, irregular tumor border, arterial enhancement due to minute intratumoral blood sinusoids, and hypoenhancement in the late vascular phase.

Papillary adenoma arising in the left hepatic duct: an unusual tumour in an uncommon location

Bile duct adenomas are rare tumours that arise more frequently in the distal extrahepatic biliary tree. We report the case of a papillary adenoma arising at the junction of the common and left hepatic ducts and review the available literature on this rare entity. A 73-year-old lady presented with a history of mild weight loss and vague upper abdominal pain. Routine blood tests revealed an elevated c-glutaryl transferase, and an ultrasound scan showed gross dilatation of the intrahepatic and extrahepatic biliary tree. Subsequent radiological imaging confirmed biliary dilatation and identified tumour within the left and common hepatic ducts with the provisional diagnosis of cholangiocarcinoma. At laparotomy, there was no evidence of extraductal tumour, and choledochoscopy showed a papillary lesion within the common hepatic and proximal left hepatic ducts. The tumour was excised and the biliary tree was reconstructed. Histological evaluation of the resected specimen confirmed a papillary adenoma with mild dysplasia. This case illustrates that not all biliary tumours are cholangiocarcinomas and referral to a hepatopancreaticobiliary unit for investigation and treatment is mandatory for all cases of obstructive jaundice.

Characteristics of bile duct carcinoma with superficial extension in the epithelium

BACKGROUND

Longitudinal tumor extension from the main tumor involves intramural or superficial spread along the bile duct, which influences surgical curability. Identifying the range of superficial extension is difficult by preoperative imaging. To clarify specific characteristics of bile duct carcinoma (BDC) with superficial extension of epithelium in the bile duct, we examined clinicopathologic features and patient outcomes in BDC patients with or without superficial extension who underwent surgical resection.

METHODS

Between 1994 and 2008, we retrospectively examined clinicopathologic findings and outcomes for 42 BDC patients who underwent surgical resection and divided them into two groups: (1) superficial extension (SE) group (n = 10); and (2) non-SE group (n = 32).

RESULTS

In terms of macroscopic growth of the main tumor, the papillary type was more common in the SE group than in the non-SE group, whereas the nodular type was dominant in the non-SE group. The prevalence of cancer-positive findings at the cut end of the bile duct was higher in the SE group. Portal vein invasion was not observed in the SE group, and the prevalence of regional lymph node metastasis was significantly greater in the non-SE group than in the SE group. No patients died of cancer in the SE group, who tended to show better survival than the non-SE group.

CONCLUSIONS

The present results suggest that a good prognosis may be achieved in BDC patients with SE when complete resection is accomplished.

Differential CT features of intraductal biliary metastasis and double primary intraductal polypoid cholangiocarcinoma in patients with a history of extrabiliary malignancy

OBJECTIVE

The purpose of this study was to discern clinical and imaging features for differentiating intraductal metastasis from double primary intraductal cholangiocarcinoma in patients with a history of extrabiliary malignant disease.

MATERIALS AND METHODS

Over a 10-year period, the cases of 14 patients with histopathologically proven intraductal metastasis (n = 8) or double primary intraductal cholangiocarcinoma (n = 6) who had a history of extrabiliary malignancy were identified. Two radiologists retrospectively reviewed CT (n = 14) and MR (n = 6) images for the size and appearance of the intraductal lesion, presence of a parenchymal mass, multiplicity, attenuation on arterial and portal phase images, and presence of calcification. Clinical findings such as the location of extrabiliary malignancy and presence of Clonorchis sinensis infestation also were recorded. Univariate tests were used to differentiate the two disease entities.

RESULTS

Histopathologic confirmation was obtained by surgical resection (n = 12) or ultrasound-guided biopsy (n = 2). All intraductal metastatic lesions were of colorectal cancer, and all intraductal cholangiocarcinomas were associated with extracolonic malignant disease, including three cases of gastric cancer (p < 0.0001). All cholangiocarcinomas manifested themselves as purely intraductal masses, but five of the eight intraductal metastatic lesions were contiguous with parenchymal masses (p = 0.031). The appearance of the intraductal lesion was predominantly expansile in cases of metastasis (seven of eight cases) but not in cases of cholangiocarcinoma (one of six cases) (p = 0.026). Other findings were not statistically significant in differentiating the two disease entities.

CONCLUSION

When an intraductal lesion is found in a patient with extrabiliary malignancy, the presence of a contiguous parenchymal mass, an expansile nature of the intraductal lesion, and a history of colorectal cancer may suggest the presence of intraductal metastasis rather than double primary intraductal cholangiocarcinoma.

Intraductal papillary mucinous tumor of bile ducts radiologic and pathologic features: a case report

We report a case of a 67-year-old Caucasian man with right upper quadrant abdominal pain. He underwent radiologic investigations that revealed a solid, focal mass, at the V hepatic segment. Because a definitive diagnosis, based on imaging appearance of the lesion, was impossible in our case, we performed a hystopathological investigation but the biopsies were inconclusive. So, the definitive diagnosis of intraductal papillary mucinous tumor of bile ducts was made on surgical resected material.

Intraductal papillary neoplasm of the liver (IPNL) is a recently recognized entity which closely resembles an intraductal papillary mucinous tumor (IPMT) of the pancreas.

Endoscopic retrograde cholangiography in the diagnosis and treatment of mucobilia

OBJECTIVE

Some biliary neoplasms secrete copious mucin into bile ducts, yet the management of mucobilia is not well known. The objective of this study was to analyze 16 patients with copious mucin in the biliary tract stressing the diagnostic and therapeutic aspects of endoscopic retrograde cholangiography (ERC).

MATERIAL AND METHODS

Sixteen patients with mucobilia were found among 5635 cases of ERC from October 1999 to October 2006 in our institution. Diagnostic and therapeutic ERC as well as clinical features were retrospectively analyzed.

RESULTS

Mucin had a greater impact than the neoplasm itself on the cholangiogram and clinical presentation. ERC failed to show the tumors but a disproportionate or aneurysmal dilatation of the segmental or lobar duct correlated with the tumor-bearing duct was evident. Endoscopic managements included clearance of intraductal mucin and/or endoscopic nasobiliary drainage (ENBD). Three patients were excluded from outcome assessment because of non-specific symptoms or spontaneously subsiding jaundice. Among the 13 patients eligible for assessment, subjective improvement in symptoms and/or a decrease in jaundice along with subsiding cholangitis following ERC was observed in 5 of the 7 patients that underwent both clearance of intraductal mucin and ENBD (ENBD function was poor in all 7 patients), in 1 patient who underwent only clearance of intraductal mucin, and in 3 of the 5 patients who underwent only ENBD. The three patients with progressive jaundice, despite endoscopic management, had advanced disease.

CONCLUSIONS

ERC revealed the tumor-bearing duct but not the extent of the disease in most of the patients with mucobilia. When mucobilia is encountered during ERC, the management should include clearance of as much intraductal mucin as possible. ENBD is frequently obstructed by mucin and may be helpful only in selected cases.

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.

Enhancement characteristics of cholangiocarcinomas on mutiphasic helical CT: emphasis on morphologic subtypes

PURPOSE

The purpose of this study was to characterize the differences in CT enhancement pattern among the morphologic subtypes of cholangiocarcinomas.

MATERIALS AND METHODS

Unenhanced, hepatic arterial (HAP), and portal venous phase (PVP) CT images of 84 patients with pathologically proven cholangiocarcinoma were retrospectively reviewed. Tumors were of the following types: 27 mass-forming, 39 periductal-infiltrating, and 18 intraductal. The CT attenuation values of tumors were measured at each phase. The tumor enhancement ratio (ER) on HAP and PVP was calculated.

RESULTS

Each cholangiocarcinoma subtype produced characteristic enhancement relative to liver on HAP and PVP images: mass-forming tumors demonstrated hyperenhancing periphery and hyopenhancing centers; periductal-infiltrating tumors, hyperenhancing; and intraductal tumors, hypoenhancing. The ER of the tumor types was significantly different (P<.001, HAP, PVP): periductal-infiltrating tumors showed the highest ER (2.5; 3.8); the centers of mass-forming tumors, lowest (1.5; 2.2); the peripheries of mass-forming tumors, high (2.1; 3.0); intraductal tumors, low (1.9; 2.6).

CONCLUSION

Cholangiocarcinoma subtypes tended to exhibit distinct enhancement characteristics. Knowledge of these enhancement patterns may aid diagnosis and surgical planning.

Biliary cystic intraductal papillary mucinous tumor and cystadenoma/cystadenocarcinoma: differentiation by CT

PURPOSE

To identify differential findings of biliary cystic intraductal papillary mucinous tumor (IPMT) and biliary cystadenoma/cystadenocarcinoma on CT images.

MATERIALS AND METHODS

Records of 7 patients with biliary cystic IPMT and 17 patients with biliary cystadenoma/cystadenocarcinoma were accessed. A pathologist reviewed gross morphologic and microscopic findings and confirmed the diagnosis. Two radiologists who were blind to the pathologic diagnosis reviewed CT images regarding size of cystic mass, mural nodule, septa, calcification, dilatation of the proximal, and distal bile ducts to the tumor, and the results were analyzed using multivariate analysis.

RESULTS

Mural nodule and dilatation of the bile ducts distal to the cystic tumor were more commonly seen in patients with cystic IPMT than in patients with biliary cystadenoma/cystadenocarcinoma and these are statistically significant, the P values being 0.029 and 0.016, respectively. Size of the cystic tumor, presence of septa, calcification, and dilatation of the bile duct proximal to the cystic tumor were not statistically different.

CONCLUSION

Biliary cystic IPMT could be differentiated from biliary cystadenoma/cystadenocarcinoma on CT images based on the presence of mural nodules and dilatation of the bile ducts distal to the cystic tumor.

Primary Cancer of the Liver and Biliary Duct

F-18-FDG PET and PET/CT are useful for staging, predicting the prognosis, and evaluating recurrence and treatment response in hepatocellular carcinomas (HCCs) and cholangiocarcinomas. Increased F-18-FDG uptake within tumors could be a surrogate marker of aggressive behavior and poor clinical outcome, despite high false-negative rates in detecting primary intrahepatic low-grade HCCs and periductal-infiltrating cholangiocarcinomas. Dualtracer PET or PET/CT using carbon-11-acetate and F-18-FDG will increase diagnostic performance in HCC.

Gadobenate dimeglumine-enhanced MRI of intraductal papillary mucinous tumor of the bile ducts

We present the case of a 63-year-old male with intraductal papillary mucinous tumor (IPMT) of the bile ducts. We discuss the role of gadobenate dimeglumine (Gd-BOPTA)-enhanced T1-weighted MRI in the visualization of mucin flow, localization of the papillary tumor, and confirming the diagnosis of this uncommon disease.

Cholangiographic spectrum of intraductal papillary mucinous neoplasm of the bile ducts

OBJECTIVE

To propose a cholangiographic classification for intraductal growth type intrahepatic cholangiocarcinoma (IG-ICC) and its precursor, collectively termed intraductal papillary mucinous neoplasm of the bile ducts (IPMN-B).

SUMMARY BACKGROUND DATA

For the extensive clinicopathologic variations of IPMN-B, a detailed characterization of cholangiography for IPMN-B is beneficial for determining the optimal therapeutic strategy.

METHODS

A total of 124 patients with cholangiography-available and pathologically proven IPMN-B were retrospectively studied. Numbers of IPMN-B type 1, type 2, type 3, and type 4 were 33, 17, 15, and 59, respectively. A cholangiographic classification was proposed based on the presence of hepatolithiasis, mucobilia, neoplasia localization, and concomitant malignancies. The demographics, histologic grading, management, and survival were also analyzed.

RESULTS

All 33 IPMN-B type 1 and 12 of 17 IPMN-B type 2 displayed cholangiographic pattern IA demonstrating hepatolithiasis-related biliary stricture. The remaining 5 IPMN-B type 2 displayed cholangiographic pattern IB or IC, which demonstrated mucobilia without discernible neoplasia. Seven of 15 IPMN-B type 3 and 52 of the 59 IPMN-B type 4 displayed cholangiographic pattern IIA or IIB, which demonstrated overt intraductal neoplasia. Seven IPMN-B type 3 or 4 displayed cholangiographic pattern IIIA or IIIB, which demonstrated IPMN-B and concomitant malignancies. For those presenting with cholangiographic pattern IA, IC, IIA, IIB, and IIIA, straightforward hepatectomies for the diseased lobes were performed. For those with pattern IB, surgical resections were performed only when there was emergence of mucin-producing neoplasia. For those with IIIB, the concomitant malignancies were considered inoperable. No disease-related death occurred in IPMN-B type 1and 2. The mean survival rates of IPMN-B type 3 and type 4 were 55.5 +/- 17.1 months and 36.9 +/- 6.3 months, respectively.

CONCLUSION

The presented cholangiographic classification facilitates the management for IPMN-B. Significant survival discrepancy at the various stages warrants a more aggressive surgical strategy.

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

Intraductal papillary neoplasm of the bile duct (IPNB) or liver is a recently noted rare disease, and its pathogenesis remains unclear. Here we present a case of IPNB with an interesting morphology, which was treated by resection of the right hemiliver and extrahepatic bile duct. A 79-year-old woman was found to have a high alkaline phosphatase level and slight dilatation of the right intrahepatic bile duct on imaging studies. The right intrahepatic bile duct became dilated over a 2-year period; however, no solid mass could be detected, and tumor markers were not elevated. Hepatic resection was scheduled because a mucin-producing bile duct carcinoma of the liver was suspected. A right hemihepatectomy was conducted, and the extrahepatic bile duct was also resected after malignant cells were found in the surgical stump of the right bile duct and in the bile itself. Macroscopically, diffuse dilatation of the intrahepatic bile duct was noted, but no solid component or mucin within the duct was found. Histopathological findings revealed carcinoma in situ, IPNB, in the majority of intrahepatic bile ducts, with no lymph node metastasis, and it extended continuously to the epithelium of the common bile duct. No tumor recurrence or biliary dilatation was observed at follow-up 2 years after surgery. It is important to consider malignancy in the presence of a dilated bile duct and in the absence of any cause of occlusion. Complete resection of IPNB results in a good prognosis and no recurrence.

Intraductal papillary mucinous tumor of the bile ducts

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.

Papillary neoplasms of the bile duct that mimic biliary stone disease

Papillary tumors of the bile duct are intraductal tumors with innumerable minute, frondlike papillary projections. These tumors may be either fixed to or detached from the bile duct wall. However, because the papillary projections on the surface of papillary tumors are long and slender, the tumors are friable and slough easily. The sloughed tumor fragments may float within the bile ducts, resulting in intermittent partial biliary obstruction and mimicking bile duct stones at clinical examination and at ultrasonography (US), computed tomography (CT), and cholangiography. A tumor manifests radiologically as thickening and irregularity of the bile duct wall or as a fixed or sloughed intraductal mass. A nonshadowing intraductal echogenic cast seen at US, an intraductal noncalcified soft-tissue mass with asymmetric wall thickening seen at CT, and an intraductal mass with a papillary surface and a serrated bile duct margin seen at cholangiography are all appearances that suggest a papillary tumor and may be helpful in differentiating a tumor from a bile duct stone.

Radiological spectrum of intraductal papillary tumors of the bile ducts

Papillary tumor of the bile duct is characterized by the presence of an intraductal tumor with a papillary surface comprising innumerable frondlike infoldings of proliferated columnar epithelial cells surrounding slender fibrovascular stalks. There may be multiple tumors along the bile ducts (papillomatosis or papillary carcinomatosis), which are dilated due to obstruction by a tumor per se, by sloughed tumor debris, or by excessive mucin. Radiologically, the biliary tree is diffusely dilated, either in a lobar or segmental fashion, or aneurysmally, depending on the location of the tumor, the debris, and the amount of mucin production. A tumor can be depicted by imaging as an intraductal mass with a thickened and irregular bile duct wall. Sloughed tumor debris and mucin plugs should be differentiated from bile duct stones. Cystically or aneurysmally, dilated bile ducts in mucin-hypersecreting variants (intraductal papillary mucinous tumors) should be differentiated from cystadenoma, cystadenocarcinoma and liver abscess.

Radiologic spectrum of cholangiocarcinoma: emphasis on unusual manifestations and differential diagnoses

Most cholangiocarcinomas are ductal adenocarcinomas that arise from both intra- and extrahepatic bile duct epithelium, and their typical growth pattern can be classified as exophytic, infiltrative, polypoid, or a combination of these. Those of unusual histologic type (eg, mucin-hypersecreting cholangiocarcinoma, squamous adenocarcinoma, biliary cystadenocarcinoma, and mucinous carcinoma) show a growth pattern different from that of the typical ones (ie, ductal). Cholangiocarcinomas frequently develop in patients with any of a variety of preexisting bile duct diseases, some of which are considered precursors of cholangiocarcinoma (eg, biliary lithiasis, clonorchiasis, recurrent pyogenic cholangitis, and primary sclerosing cholangitis). Some bulky hepatic tumors of either primary or secondary origin mimic exophytic peripheral cholangiocarcinoma. Some variants of hepatocellular carcinoma, such as sclerosing, fibrolamellar, and cholangiohepatocellular carcinoma, resemble exophytic peripheral cholangiocarcinoma, while that with intraductal growth resembles polypoid cholangiocarcinoma. Among benign bile duct diseases, tumorous conditions (eg, benign biliary tumors) may mimic polypoid cholangiocarcinoma, whereas benign stricture of various causes (eg, cholangitides, traumatic and postsurgical sequelae, chronic pancreatitis, papillary stenosis) usually mimics infiltrative cholangiocarcinoma.