Pathological classification of intrahepatic cholangiocarcinoma based on a new concept

Intrahepatic cholangiocarcinoma (ICC) arises from the lining epithelium and peribiliary glands of the intrahepatic biliary tree and shows variable cholangiocytic differentiation. To date, ICC was largely classified into adenocarcinoma and rare variants. Herein, we propose to subclassify the former, based on recent progress in the study of ICC including the gross classification and hepatic progenitor/stem cells and on the pathological similarities between biliary and pancreatic neoplasms. That is, ICC is classifiable into the conventional (bile duct) type, the bile ductular type, the intraductal neoplasm type and rare variants. The conventional type is further divided into the small duct type (peripheral type) and large bile duct type (perihilar type). The former is a tubular or micropapillary adenocarcinoma while the latter involves the intrahepatic large bile duct. Bile ductular type resembles proliferated bile ductules and shows a replacing growth of the hepatic parenchyma. Hepatic progenitor cell or stem cell phenotypes such as neural cell adhesion molecule expression are frequently expressed in the bile ductular type. Intraductal type includes papillary and tubular neoplasms of the bile duct (IPNBs and ITNBs) and a superficial spreading type. IPNB and ITNB show a spectrum from a preneoplastic borderline lesion to carcinoma and may have pancreatic counterparts. At invasive sites, IPNB is associated with the conventional bile duct ICC and mucinous carcinoma. Biliary mucinous cystic neoplasm with ovarian-like stroma in its wall is different from IPNB, particularly IPNB showing cystic dilatation of the affected ducts. Rare variants of ICC include squamous/adenosquamous cell carcinoma, mucinous/signet ring cell carcinoma, clear cell type, undifferentiated type, neuroendocrine carcinoma and so on. This classification of ICC may open up a new field of research of ICC and contribute to the clinical approach to ICC.     

A statement by the Japan‐Korea expert pathologists for future clinicopathological and molecular analyses toward consensus building of intraductal papillary neoplasm of the bile duct through several opinions at the present stage

Intraductal papillary neoplasm of bile duct (IPNB) was described as a preinvasive neoplastic lesion of the biliary tract in the 2010 World Health Organization (WHO) classification. Although a number of studies have since been conducted on IPNBs, controversy remains, particularly regarding the standardization of its definition. Meetings by Japanese and Korean expert pathologists were held twice to resolve the pathological diagnostic aspects of IPNB. Through round‐table discussions and histological reviews, we reached the common understanding that IPNBs diagnosed according to the criteria of WHO 2010 are characterized by intraductal predominant papillary or villous biliary neoplasms covering delicate fibrovascular stalks and are classified into two types pathologically. One type (type 1 IPNB) is histologically similar to intraductal papillary mucinous neoplasms of pancreas, and typically develops in the intrahepatic bile ducts, while the other (type 2 IPNB) has a more complex histological architecture with irregular papillary branching or with foci of solid‐tubular components and typically involves the extrahepatic bile ducts. This report states the diagnostic pathologic features of IPNB proposed by WHO 2010. Since currently, the concept of IPNB is still confusing, the proposed diagnostic pathologic features stated here will be of use for future clinicopathological and molecular analyses toward consensus building of IPNB.     

A Case in which an Intraductal Papillary Neoplasm of the Bile Duct Was Surgically Resected 12 Years after the Initial Diagnosis

A 66-year-old Japanese man was referred to our hospital with multiple giant liver cysts. The cysts had already been detected as multiple 3-cm cysts with small nodules at another hospital 12 years prior to this presentation. The cysts were diagnosed as an intraductal papillary neoplasms of the bile duct (IPNB) occupying the right lobe of the liver. Extended right lobectomy was performed. Based on the pathological findings, the tumor was diagnosed to be an oncocytic-type IPNB with minimal invasion. This experience suggests that the progression of IPNBs occur relatively slowly. The present case might provide important information for understanding the natural history of IPNBs.     

Intraductal papillary neoplasm of the bile duct: A biliary equivalent to intraductal papillary mucinous neoplasm of the pancreas?

Intraductal papillary neoplasm of the bile duct (IPNB) is a variant of bile duct carcinoma characterized by intraductal growth and better outcome compared with the more common nodular-sclerosing type. IPNB is a recognized precursor of invasive carcinoma, but its pathogenesis and natural history are ill-defined. This study examines the clinicopathologic features and outcomes of IPNB. A consecutive cohort of patients with bile duct cancer (hilar, intrahepatic, or distal) was reviewed, and those with papillary histologic features identified. Histopathologic findings and immunohistochemical staining for tumor markers and for cytokeratin and mucin proteins were used to classify IPNB into subtypes. Survival data were analyzed and correlated with clinical and pathologic parameters. Thirty-nine IPNBs were identified in hilar (23/144), intrahepatic (4/86), and distal (12/113) bile duct specimens between 1991 and 2010. Histopathologic examination revealed 27 pancreatobiliary, four gastric, two intestinal, and six oncocytic subtypes; results of cytokeratin and mucin staining were similar to those of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. Invasive carcinoma was seen in 29/39 (74%) IPNBs. Overall median survival was 62 months and was not different between IPNB locations or subtypes. Factors associated with a worse median survival included presence and depth of tumor invasion, margin-positive resection, and expression of MUC1 and CEA. Conclusion: IPNBs are an uncommon variant of bile duct cancer, representing approximately 10% of all resectable cases. They occur throughout the biliary tract, share some histologic and clinical features with IPMNs of the pancreas, and may represent a carcinogenesis pathway different from that of conventional bile duct carcinomas arising from flat dysplasia. Given their significant risk of harboring invasive carcinoma, they should be treated with complete resection. (HEPATOLOGY 2012).     

Anatomical,histomorphological and molecular classification of cholangiocarcinoma

Cholangiocarcinoma constitutes a heterogeneous group of malignancies that can emerge at any point of the biliary tree. Cholangiocarcinoma is classified into intrahepatic, perihilar and distal based on its anatomical location. Histologically, conventional perihilar/distal cholangiocarcinomas are mucin‐producing adenocarcinomas or papillary tumours; intrahepatic cholangiocarcinomas are more heterogeneous and can be sub‐classified according to the level or size of the displayed bile duct. Cholangiocarcinoma develops through multistep carcinogenesis and is preceded by dysplastic and in situ lesions. Definition and clinical significance of precursor lesions, including biliary intraepithelial neoplasia, intraductal papillary neoplasms of the bile duct, intraductal tubulopapillary neoplasms and mucinous cystic neoplasm, are discussed in this review. A main challenge in diagnosing cholangiocarcinoma is the fact that tumour tissue for histological examination is difficult to obtain. Thus, a major clinical obstacle is the establishment of the correct diagnosis at a tumour stage that is amenable to surgery which still represents the only curable therapeutic option. Current standards, methodology and criteria for diagnosis are discussed. Cholangiocarcinoma represents a heterogeneous tumour with regard to molecular alterations. In intrahepatic subtype, mainly two distinctive morpho‐molecular groups can currently be discriminated. Large‐duct type intrahepatic cholangiocarcinoma shows a high mutation frequency of oncogenes and tumour suppressor genes, such as KRAS and TP53 while Isocitrate Dehydrogenase 1/2 mutations and Fibroblast Growth Factor Receptor 2‐fusions are typically seen in small‐duct type tumours. It is most important to ensure the separation of the given anatomical subtypes and to search for distinct subgroups within the subtypes on a molecular and morphological basis.     

Intraductal papillary mucinous neoplasm of the biliary tract with cardiac metastasis: A case report

Introduction:Intraductal papillary mucinous neoplasm of the biliary tract (IPNB) is a rare, low-grade neoplasm limited to the bile duct mucosa. The malignant transformation rate is low, and there have been limited reports of metastasis to other organs. Herein, we presented a rare case of a patient who was diagnosed with IPNB concurrent with invasive adenocarcinoma after surgery and was diagnosed with cardiac metastasis 6 months later.Patient concerns:A 61-year-old male patient presented with abdominal pain to a local clinic. He was diagnosed with intrahepatic cholangiocarcinoma with pancreatitis and transferred to our hospital.Diagnosis:Diagnostic testing (magnetic resonance imaging, endoscopic retrograde cholangiopancreatography, positron emission tomography-computed tomography) revealed a papillary neoplasm and invasive adenocarcinoma with papillary neoplasm in the periampullary lesion.Interventions:Pancreaticoduodenectomy, right hemihepatectomy, and left lateral sectionectomy of the liver were performed. After surgery, we planned gemcitabine-based adjuvant chemotherapy.Outcomes:Upon completion of the sixth gemcitabine chemotherapy cycle, a hyperechoic, oval-shaped mass (1.3 × 2.6 cm) was found on the outer wall of the right atrium. Resection of a cardiac tumor in the right atrium and patch repair were performed.Conclusion:To our knowledge, no other case of cardiac metastasis found during observation after surgery for an IPNB has been described. IPNBs are known to be less aggressive and to have a lower metastasis rate than intraductal papillary mucinous neoplasms; therefore, the number of case reports describing metastasis after surgery is relatively low. Our case suggests that close observation is necessary in patients diagnosed with an IPNB.     

Intrahepatic biliary papilloma morphologically similar to biliary cystadenoma

A 37-year-old man presented complaining of epigastralgia. Abdominal ultrasonography revealed the presence of a papillary tumor (9 mm in diameter) in the cystic lesion (18 mm in diameter) in hepatic segment 4, which was accompanied by mild intrahepatic bile duct dilatation. Although abdominal computed tomography also showed the cystic lesion, it did not show papillary tumors inside the lesion. Endoscopic retrograde cholangiography showed the communication between the cystic lesion and the left hepatic duct. In addition, mucus was observed in the common bile duct. When transpapillary intraductal ultrasonography was performed through the left hepatic duct using a fine ultrasonic probe, a hyperechoic papillary and lobulated tumor was clearly shown in the cystic lesion. The wall of the cyst was smooth and there was no sign of tumor infiltration. Based on these findings, biliary cystadenoma was diagnosed and an extended left lobectomy was carried out. However, pathological findings postoperatively revealed that the lesion was a localized biliary papilloma, developing and extending to the intrahepatic duct. This case is rare and there have been no published reports describing a biliary papilloma morphologically similar to biliary cystadenoma.     

Management of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a distinct entity characterized by papillary proliferations of mucin-producing epithelial cells with excessive mucus production and cystic dilatation of the pancreatic ducts. IPMNs have malignant potential and exhibit a broad histologic spectrum, ranging from adenoma to invasive carcinoma. IPMNs are classified into main duct and branch duct types, based on the site of tumor involvement. IPMN patients have a favorable prognosis if appropriately treated. The postoperative 5-year survival rate is nearly 100% for benign tumors and noninvasive carcinoma, and approximately 60% for invasive carcinoma. A main duct type IPMN should be resected. Surgical treatment is indicated for a branch duct IPMN with suspected malignancy (tumor diameter ≥ 30 mm, mural nodules, dilated main pancreatic duct, or positive cytology) or positive symptoms. Malignant IPMNs necessitate lymph node dissection (D1). IPMNs are associated with a high incidence of extrapancreatic malignancies and pancreatic ductal carcinoma.     

Intraductal papillary neoplasm of the bile duct

Intraductal papillary neoplasm of the bile duct(IPNB)is a variant of bile duct carcinoma that is characterized by intraductal growth and better outcomes compared with common cholangiocarcinoma.IPNBs are mainly found in patients from Far Eastern areas,where hepatolithiasis and clonorchiasis are endemic.According to the immunohistochemical profiles of the mucin core proteins,IPNBs are classified into four types:pancreaticobiliary,intestinal,gastric,and oncocytic.Approximately 40%-80%of IPNBs contain a component of invasive carcinoma or tubular or mucinous adenocarcinoma,suggesting that IPNB is a disease with high potential for malignancy.It is difficult to make an accurate preoperative diagnosis because of IPNB’s low incidence and the lack of specificity in its clinical manifestation.The most common abnormal preoperative imaging findings of IPNB are intraductal masses and the involvement of bile duct dilation.Simultaneous proximal and distal bile duct dilation can be detected in some cases,which has diagnostic significance.Cholangiography and cholangioscopy are needed to confirm the pathology and demonstrate the extent of the lesions.However,pathologic diagnosis by biopsy cannot reflect the actual stage in many cases because different foci may be of different stages and because mixed pathologic findings may exist in the same lesion.Surgical resection is the major treatment.Systematic cholangioscopy with staged biopsies and frozen sections is recommended during resection to ensure that no minor tumors are left and that curative resection is achieved.Staging,histologic subtype,curative resection and lymph node metastasis are factors affecting long-term survival.     

Multicentric pancreatic intraepithelial neoplasias (PanINs) presenting with the clinical features of chronic pancreatitis

A 46-year-old woman was readmitted to our hospital in August 2005 because of severe abdominal pain and nausea. Computed tomography demonstrated a huge cystic lesion in the retroperitoneal space behind the hepatoduodenal ligament and lesser peritoneal cavity. Endoscopic retrograde pancreatography revealed communication between the dilated main pancreatic duct and a pseudocyst. The condition was preoperatively diagnosed as chronic pancreatitis associated with a pseudocyst or an intraductal papillary mucinous neoplasm without mucin hypersecretion. The patient underwent a distal pancreatectomy with splenectomy. The pathologic diagnosis was multicentric pancreatic intraepithelial neoplasia (PanIN), and histological examination revealed a positive surgical margin around the remnant pancreas. Four months after the surgery, the patient underwent a total pancreatectomy. Macroscopic observation revealed diffuse fibrosis of the pancreatic parenchyma compatible with chronic pancreatitis. Histological examination revealed a constellation of noninvasive intraductal neoplasias with high-grade atypia, diffusely distributed in the small pancreatic ducts of the resected pancreas. Localized fibrosis and cystic dilation of the small ducts were detected in a lobule of exocrine glands draining into a ductule involved by PanIN lesions in the head of the pancreas. In summary, multicentric PanIN lesions are associated with lobular atrophy of the pancreatic parenchyma and chronic pancreatitis-like changes that follow. Total pancreatectomy may be recommended for patients with multicentric precursor lesions throughout the entire pancreas.     

Clinical aspects of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) is a spectrum of neoplasia in the pancreatic duct epithelium characterized by cystic dilation of the main and/or branch pancreatic duct. According to the site of involvement IPMNs are classified into three categories, i.e., main duct type, branch duct type, and combined type. Most branch duct IPMNs are benign, whereas the other two types are often malignant. A large size of branch duct IPMN and marked dilation of the main pancreatic duct indicate the presence of adenoma at least. The additional existence of large mural nodules increases the possibility of malignancy in all types. Of recent interest is the relatively high prevalence of synchronous and/or metachronous malignancy in various organs, including the pancreas. The prognosis is favorable after complete resection of benign and noninvasive malignant IPMNs. Malignant IPMNs acquiring aggressiveness after parenchymal invasion necessitate adequate lymph node dissection. On the other hand, asymptomatic branch duct IPMNs without mural nodules can be observed without resection for a considerably long time. This review addresses available data, current understanding, controversy, and future directions.     

The clinicopathological features of biliary intraductal papillary neoplasms according to the location of tumors

Background and Aim: In this study, we analyzed the clinical and pathological features of biliary intraductal papillary neoplasms (IPN‐B) according to the location of the tumors. Methods: A total of 55 patients with IPN‐B were analyzed. We divided them into three groups: common bile duct (CBD), hilar, and intrahepatic duct (IHD) groups. The clinical and laboratory findings, cell types, depth of invasion, malignancy, existence of stones, lymph node metastasis, recurrence, and survival rate were analyzed. Results: There was no difference in the depth of invasion, lymph node metastasis, and coexistence of stones between the three groups. There were four different cell types; the intestinal cell type was the most common type in each group. The gastric cell type was prevalent in the IHD and hilar groups (58.3% and 33.3%, respectively). Invasive colloid carcinoma mainly showed the intestinal cell type, and tubular carcinoma showed the pancreaticobiliary cell type. There was a trend that malignancy was more prevalent in the CBD group (94.1%) than in the hilar group (64.3%) and IHD group (79.2%), but there was no statistically significant difference. There was no difference in the recurrence rate and the 3‐year survival rate between the three groups. Conclusion: IPN‐B showed no difference in the malignancy and survival rates according to the location of the tumors. Because IPN‐B show good prognosis after surgery, aggressive surgical resection for the treatment of IPN‐B is recommended.     

Intraductal oncocytic papillary neoplasm of the bile duct: the first case of peribiliary gland origin

We report herein the first case of intraductal oncocytic papillary neoplasm of the bile duct arising from a peribiliary gland of the left hepatic duct. The patient was a 63-year-old Japanese man. Radiological and cholangioscopic examinations revealed intraductal tumor of the left hepatic duct. After pathological diagnosis of adenocarcinoma by cholangioscopic biopsy, a surgical hepatobiliary resection was performed. Pathological examination revealed papillary tumor in the left hepatic duct. Histologically, the tumor was identified as papillary neoplasm comprising oncocytic cells and delicate fibrovascular cores. Interestingly, this tumor originated from the cystic space in the bile duct wall. This cystic space was histologically identified as a cystically dilated peribiliary gland. Carcinoma in situ was observed in this cystic peribiliary gland at the bottom of the tumor, but not on any areas of biliary epithelium. This case suggests that intraductal papillary neoplasm can arise from both biliary epithelium and peribiliary glands.     

Laparoscopic resection of synchronous intraductal papillary mucinous neoplasms: A case report

We describe herein a 68-year-old woman who was diagnosed with a quite rare entity of intraductal papillary mucinous neoplasms (IPMNs) occurring simultaneously in the left lateral lobe of liver and the tail of pancreas. Abdominal computed tomography and magnetic resonance cholangiopancreatography showed a cystic dilatation of the pancreatic duct in the pancreatic tail, which suggested an IPMN, and multiple intrahepatic duct stones in the left lateral lobe. The patient underwent a laparoscopic left lateral hepatolobectomy and spleen-preserving distal pancreatectomy. Intra-operative finding of massive mucin in the dilated bile duct implied an intraductal mucinous tumor in the liver. The diagnosis of synchronous IPMNs in the liver and pancreas was confirmed by pathological examination. The patient was followed up for 6 mo without signs of recurrence. Although several cases of IPMN of liver without any pancreatic association have been reported, the simultaneous occurrence of IPMNs in the liver and pancreas is very rare. To the best of our knowledge, it is the first reported case treated by laparoscopic resection.     

Simultaneous liver mucinous cystic and intraductal papillary mucinous neoplasms of the bile duct:A case report

Cystic hepatic neoplasms are rare tumors,and are classified into two separate entities:mucinous cystic neoplasms(MCNs)and intraductal papillary mucinous neoplasms of the bile duct(IPMN-B).We report the case of a 56-year-old woman who presented with abdominal pain and jaundice due to the presence of a large hepatic multilocular cystic tumor associated with an intraductal tumor.Partial hepatectomy with resection of extrahepatic bile ducts demonstrated an intrahepatic MCN and an intraductal IPMN-B.This is the first report of the simultaneous occurrence of these two histologically distinct entities in the liver.     

Clinical importance of precursor lesions in the pancreas

Three distinct noninvasive precursor lesions to invasive ductal adenocarcinoma of the pancreas have been described. These include the mucinous cystic neoplasm, intraductal papillary mucinous neoplasm, and pancreatic intraepithelial neoplasia. The early detection and treatment of these lesions can interrupt the progression of a curable noninvasive precursor to an almost uniformly deadly invasive cancer.     

Differential diagnosis of intraductal papillary‐mucinous tumor of the pancreas by endoscopic ultrasonography and intraductal ultrasonography

Background: Intraductal papillary‐mucinous tumor (IPMT) of the pancreas has a broad spectrum of histology ranging from hyperplasia to adenocarcinoma. Therefore, it is important to differentiate between the malignant and benign lesions to determine the therapeutic strategy for IPMT. Patients and Methods: Thirty‐nine patients with IPMT (27 men and 12 women, mean age: 63.3 years) underwent surgery between January 1985 and March 2002. The size of the cystic lesion, the maximum diameter of the main pancreatic duct (MPD), and the height of the papillary tumor inside the cyst were investigated by endoscopic ultrasonography (EUS) and/or intraductal ultrasonography (IDUS) before operation. These preoperative clinical findings were compared with the pathological findings of the resected specimen. Results: The size of the cystic lesion, the diameter of MPD, and the height of the papillary tumor in cases with malignant IPMT (invasive and non‐invasive carcinoma) were larger than those in cases with benign IPMT (adenoma and hyperplasia). Analysis of the images of the lesions revealed that the following three factors are important for diagnosing IPMT: (i) the size of the cystic lesion is ≥ 30 mm; (ii) the diameter of MPD is ≥ 8 mm; (iii) the height of the papillary tumor inside the cyst is ≥ 3 mm. It was not significant to differentiate between benign and malignant IPMT based on factor (i), but statistically significant (P < 0.001) based on factors (ii) and (iii). Conclusions: EUS and IDUS are useful in the differential diagnosis of IPMT, especially in the differentiation between malignant and benign IPMT.     

Intrahepatic,Perihilar and Distal Cholangiocarcinoma: Management and Outcomes

Introduction and aimsCholangiocarcinomas are a heterogeneous group of tumors that can be classified into three clinically distinct types of cancers, intrahepatic, perihilar and distal cholangiocarcinoma. The inconsistent use of nomenclature for these cancers has obscured a true knowledge of the epidemiology, natural history and response to therapy of these cancers. Our aims were to define demographic characteristics, management and outcomes of these three distinct cancer types.Materials and methodsA retrospective study of patients enrolled in an institutional cancer registry from 1992 to 2010. Median survival was compared between different treatment modalities over three time periods for the three types of cholangiocarcinoma at different stages of the disease using Kaplan Meyer analysis.Results242 patients were identified. All cases were reviewed and classified into intrahepatic (90 patients), distal (48 patients) or perihilar (104 patients) cholangiocarcinomas. These cancers differed in median age of onset, gender distribution, median survival and stage. 13.8% of patients presented with stage I, 5.8% with stage II, 9.6% with stage III, 28% with stage IV, with 41.8% having unknown stage. The overall median survival was 15.8 months, and was 23, 25, 14, and 4.5 months for stages I, II, III, and IV respectively. Surgery improved survival in both early and advanced stages. Multimodality therapies further improved outcomes, particularly for perihilar cholangiocarcinoma.ConclusionPerihilar, distal and intrahepatic cholangiocarcinoma vary in their presentation, natural history and therapeutic approach to management. A consistently applied classification is essential for meaningful interpretation of studies of these cancers.     

A clinicopathological reappraisal of intraductal papillary neoplasm of the bile duct (IPNB): a continuous spectrum with papillary cholangiocarcinoma in 181 curatively resected cases

BackgroundIntraductal papillary neoplasm of the bile-duct (IPNB) has recently been further subclassified into “so-called IPNBs” (Type-1) and “narrow-sense papillary cholangiocarcinomas” (Type-2), but their differential diagnosis is challenging. This study aimed to reevaluate Type-1 and Type-2 IPNBs.MethodsConsecutive patients who underwent papillary bile-duct tumor resection were included. Using six pathological features (location, mucin secretion, histological architecture, histological type, presence of a low/intermediate-dysplasia component, and proportion of the invasive component), all papillary tumors were scored. Tumors scoring 5–6 were classified as Type-1, 0–1 as Type-2, and 2–4 as Type-Unclassifiable.ResultsThe 181 papillary bile-duct tumor patients were divided into three groups, consisting of 12 Type-1, 46 Type-2, and 123 Type-Unclassifiable—gray-zone lesions between Type-1 and Type-2 that constituted the largest proportion of papillary tumors. Type-1 tumors were pathologically the least advanced, while the other types showed gradual advancement. The 5-year survival rate was better for patients with Type-1 tumors than for those with Type-Unclassifiable or Type-2 tumors.ConclusionThe scoring system worked well to delineate a continuous spectrum of pathologic features ranging from Type-1, through Type-Unclassifiable, to Type-2, the latter two being challenging to differentially diagnose. Type-1 is regarded as an early neoplasm of Type-Unclassifiable and Type-2.     

Endoscopic diagnosis of intraductal papillary mucinous neoplasm of the bile duct

Background/Purpose

Intraductal papillary mucinous neoplasm of the bile duct (IPMN-B) is considered an uncommon tumor. The purpose of this study was to evaluate the diagnostic utility of endoscopic cholangiography (ERC) with subsequent peroral cholangioscopy (POCS) and/or intraductal ultrasonography (IDUS) for this tumor.

Methods

From December 1991 to November 2006, a retrospective analysis was made of eight patients with IPMN-B. Their clinical features and the endoscopic diagnostic strategy for POCS and IDUS were reviewed.

Results

In all the patients, ERC failed to show papillary tumors, due to coexisting mucin or biliary sludge. POCS was carried out after ERC and it showed the presence and locations of papillary tumors in all patients, except for one with a tumor in the peripheral intrahepatic bile duct (B3). IDUS was performed in seven of the eight patients; in five of these patients, intraductal protruding tumors were clearly visualized, whereas flat tumors were not identified in the remaining two patients. In one of the eight patients, endoscopic nasobiliary drainage did not remove the huge amount of mucin. Hence, this patient required subsequent percutaneous biliary drainage. Six of the eight patients underwent surgical treatment; five patients underwent a hepatic resection with or without extrahepatic bile duct resection and one underwent a pancreaticoduodenectomy. Five of the six operated patients are still alive; one patient died of gastric cancer 90 months after the operation (mean follow-up period, 45.3 months). The two remaining patients, who were considered inoperable due to major medical comorbidities, died of liver failure and cholangitis 3 and 6 months, respectively, after stent placement.

Conclusion

ERC failed to delineate intraductal papillary tumors, due to coexisting mucin. The presence and location of papillary tumors were correctly diagnosed by both POCS and IDUS, but POCS may be better than IDUS to diagnose the extent of the tumor.