Comparison of the Clinicopathologic Characteristics of Intraductal Papillary Neoplasm of the Bile Duct according to Morphological and Anatomical Classifications

A recent update on the morphological classification of intraductal papillary neoplasm of the bile duct: Correlation with postoperative prognosis and pathological features

PURPOSE

We proposed a novel morphological classification for intraductal papillary neoplasm of the bile duct (IPNB) and evaluated its association with postoperative prognosis.

METHODS

Forty-two IPNB patients who underwent surgical resection were classified morphologically into three types-branched (n = 10), main duct (n = 26), and mixed (n = 6)-based on preoperative imaging features indicating cystic and/or bile duct involvement. Among them, 32 patients with evaluable specimens were further categorized pathologically into Type 1 (n = 10) and Type 2 (n = 22). Patient characteristics and postoperative outcomes were analyzed.

RESULTS

Intraepithelial neoplasia was more frequently observed in the branched type, whereas invasive carcinoma predominated in the main duct type. In the mixed type, a half of patients involved both intra- and extrahepatic bile ducts, and this type also showed the highest incidence of residual tumor. The mixed type had the poorest 5-year postoperative survival rate (50%), compared to 90% in the main duct type and 100% in the branched type. It also exhibited the highest 5-year recurrence rate (62%). Among IPNB patients with associated invasive carcinoma, tumor infiltration beyond the bile duct wall (p < 0.001) and lymph node metastasis (p = 0.021) were significantly associated with poor prognosis, whereas the anatomical extent of the lesion (intrahepatic, extrahepatic, or both) was not. Morphological classification was significantly correlated with pathological subtypes: the branched type was predominant in Type 1 (60%), while the main duct type predominated in Type 2 (64%) (p = 0.039).

CONCLUSIONS

Our novel morphological classification of IPNB correlates with postoperative prognosis and may assist in preoperative planning of surgical strategies for IPNB patients.

Prognostic factors for intraductal papillary neoplasm of the bile duct following surgical resection: a systematic review and meta-analysis

Intraductal papillary neoplasm of the bile duct (IPNB) is a biliary neoplasm characterized by intraductal papillary growth and varying degrees of malignant transformation. This study aimed to identify effective prognostic factors (PFs) for predicting the prognosis of IPNB after surgical resection, addressing the gap in the higher level evidence. We systematically searched databases from their inception to October 10, 2023. Data on 12 predetermined PFs were collected and subjected to a meta-analysis. Forest plots were used to summarize the findings. Fifteen studies with a total of 2311 patients were included. Among the PFs examined, extrahepatic tumor location (HR, 2.97; 95% CI 1.68-5.23), subclassification type 2 (HR, 2.62; 95% CI 1.45-4.76), R1 resection (HR, 2.47; 95% CI 1.73-3.51), elevated CA19-9 level (HR, 3.25; 95% CI 1.91-5.54), tumor multiplicity (HR, 2.65; 95% CI 1.40-5.02), and adjacent organ invasion (HR, 3.17; 95% CI 2.01-5.00) were associated with a poorer prognosis. Additionally, the combined HR values indicated that lymph node metastasis and poor tumor differentiation were linked to a worse prognosis, although both exhibited significant heterogeneity. Our study offers valuable insights for enhancing postoperative prognostication and treatment decision-making for IPNB patients with IPNB. These findings warrant further validation in future prospective studies.

Intraductal Papillary Neoplasm of the Bile Duct Mimicking a Cholangiocarcinoma

The intraductal papillary neoplasm of the bile duct is a rare tumor considered one of the precursor lesions of cholangiocarcinoma. It is characterized by papillary growth within the bile duct lumen, occurring anywhere in the biliary tree. We report a case of a 70-year-old man who presented with a six-month history of weight loss and occasional choluria. An abdominal ultrasound showed a marked dilatation of the biliary tree with a polypoid intraluminal lesion. Computed tomography and magnetic resonance imaging confirmed the presence of these findings and did not reveal any secondary lesions. The patient underwent a cephalic duodenopancreatectomy yielding a diagnosis of intraductal papillary neoplasm with high-grade dysplasia.

Clinicopathological features and surgical treatments of intraductal papillary neoplasm of the bile duct: a case report and literature review

Intraductal papillary neoplasm of bile duct (IPNB), as a precancerous lesion of cholangiocarcinoma, is a rare biliary tract tumor. A 66-year-old female patient was found to have a bile duct mass by routine examination. The liver function tests and tumor markers were normal. Imaging findings revealed a 2.6 cm mass in the common hepatic duct, accompanied by dilatation of both intrahepatic and extrahepatic bile ducts. The patient underwent open extrahepatic bile duct resection, cholecystectomy and Roux-en-Y hepaticojejunostomy. We also conducted a literature review to summarize the clinicopathological features and surgical treatments of IPNB.

A Review of Type 1 and Type 2 Intraductal Papillary Neoplasms of the Bile Duct

Intraductal papillary neoplasm of the bile duct (IPNB) is a heterogeneous disease similar to intraductal papillary mucinous neoplasm of the pancreas. These lesions have been recognized as one of the three major precancerous lesions in the biliary tract since 2010. In 2018, Japanese and Korean pathologists reached a consensus, classifying IPNBs into type l and type 2 IPNBs. IPNBs are more prevalent in male patients in East Asia and are closely related to diseases such as cholelithiasis and schistosomiasis. From a molecular genetic perspective, IPNBs exhibit early genetic variations, and different molecular pathways may be involved in the tumorigenesis of type 1 and type 2 IPNBs. The histological subtypes of IPNBs include gastric, intestinal, pancreaticobiliary, or oncocytic subtypes, but type 1 IPNBs typically exhibit more regular and well-organized histological features than type 2 IPNBs and are more commonly found in the intrahepatic bile ducts with abundant mucin. Due to the rarity of these lesions and the absence of specific clinical and laboratory features, imaging is crucial for the preoperative diagnosis of IPNB, with local bile duct dilation and growth along the bile ducts being the main imaging features. Surgical resection remains the optimal treatment for IPNBs, but negative bile duct margins and the removal of lymph nodes in the hepatic hilum significantly improve the postoperative survival rates for patients with IPNBs.

Oncocytic type has distinct immunohistochemical and recurrence-free survival than other histologic types of the intraductal papillary neoplasm of the bile duct

Although intraductal oncocytic papillary neoplasm (IOPN) was considered distinct from the intraductal papillary neoplasm of the pancreas, the oncocytic histologic type remained as a subtype of intraductal papillary neoplasms of the bile duct (IPNBs) with gastric, intestinal, and pancreatobiliary types based on the fifth edition of the WHO classification. To test the characteristics of the oncocytic type of IPNBs, the histopathologic, immunohistochemical (Hep Par-1 and CD117), and clinical characteristics of 13 oncocytic type were compared with 114 others (15 gastric, 39 pancreatobiliary, and 60 intestinal) IPNB types. The oncocytic type, which occupied about 9% of IPNBs, was more frequent in females (p < 0.05) and larger (mean, 5.3 vs. 3.6 cm; p < 0.002) than other IPNB types. Immunohistochemically, the oncocytic type had more frequent combined Hep Par-1 and CD117 expression than other IPNB types (all p < 0.05). The recurrence-free survival rate for patients with the oncocytic type (5-year survival, 100%) was significantly higher (p = 0.015) than for those with other histologic types (59.9%). The oncocytic type had distinct histopathologic, immunohistochemical, and survival outcomes from other IPNBs. Therefore, it can be separated from other IPNB types and classified as one independent entity, similar to IOPN of the pancreas.

Percutaneous transhepatic cholangioscopy-assisted biliary polypectomy for local palliative treatment of intraductal papillary neoplasm of the bile duct

BACKGROUND

Intraductal papillary neoplasm of the bile duct (IPNB) is a premalignant biliary-type epithelial neoplasm with intraductal papillary or villous growth. Currently reported local palliative therapeutic modalities, including endoscopic nasobiliary drainage, stenting and biliary curettage, endoscopic biliary polypectomy, percutaneous biliary drainage, laser ablation, argon plasma coagulation, photodynamic therapy, and radiofrequency ablation to relieve mechanical obstruction are limited with weaknesses and disadvantages. We have applied percutaneous transhepatic cholangioscopy (PTCS)-assisted biliary polypectomy (PTCS-BP) technique for the management of IPNB including mucin-hypersecreting cast-like and polypoid type tumors since 2010.

AIM

To assess the technical feasibility, efficacy, and safety of PTCS-BP for local palliative treatment of IPNB.

METHODS

Patients with mucin-hypersecreting cast-like or polypoid type IPNB and receiving PTCS-BP between September 2010 and December 2019 were included. PTCS-BP was performed by using a half-moon type snare with a soft stainless-steel wire, and the tumor was snared and resected with electrocautery. The primary outcome was its feasibility, indicated by technical success. The secondary outcomes were efficacy, including therapeutic success, curative resection, and clinical success, and safety.

RESULTS

Five patients (four with mucin-hypersecreting cast-like type and one with polypoid type IPNB) were included. Low- and high-grade intraepithelial neoplasia (HGIN) and recurrent IPNB with invasive carcinoma were observed in one, two, and two patients, respectively. Repeated cholangitis and/or obstructive jaundice were presented in all four patients with mucin-hypersecreting cast-like type IPNB. All five patients achieved technical success of PTCS-BP. Four patients (three with mucin-hypersecreting cast-like type and one with polypoid type IPNB) obtained therapeutic success; one with mucin-hypersecreting cast-like type tumors in the intrahepatic small bile duct and HGIN had residual tumors. All four patients with mucin-hypersecreting IPNB achieved clinical success. The patient with polypoid type IPNB achieved curative resection. There were no PTCS-BP-related serious adverse events.

CONCLUSION

PTCS-BP appears to be feasible, efficacious, and safe for local palliative treatment of both mucin-hypersecreting cast-like and polypoid type IPNB.

Tumoral Intraductal Neoplasms of the Bile Ducts Comprise Morphologically and Genetically Distinct Entities

CONTEXT.—

Tumoral (grossly visible) intraductal neoplasms of the bile ducts are still being characterized.

OBJECTIVE.—

To investigate their morphologic, immunohistochemical, and molecular features.

DESIGN.—

Forty-one cases were classified as gastric-, intestinal-, pancreatobiliary-type intraductal papillary neoplasm (IPN), intraductal oncocytic papillary neoplasm (IOPN), or intraductal tubulopapillary neoplasm (ITPN) on the basis of histology. All neoplasms were subjected to targeted next-generation sequencing.

RESULTS.—

The mean age at diagnosis was 69 years (42-81 years); male to female ratio was 1.3. Most neoplasms (n = 23, 56%) were extrahepatic/large (mean size, 4.6 cm). The majority (n = 32, 78%) contained high-grade dysplasia, and 68% (n = 28) revealed invasion. All gastric-type IPNs (n = 9) and most ITPNs/IOPNs showed consistent colabeling for CK7/MUC6, which was less common among others (P = .004). Intestinal-type IPNs (n = 5) showed higher rates of CK20 expression than others (P < .001). Overall, the most commonly mutated genes included TP53 and APC, while copy number variants affected ELF3 and CDKN2A/B. All gastric-type IPNs contained an alteration affecting the Wnt signaling pathway; 7 of 9 (78%) showed aberrations in the MAPK pathway. Mutations in APC and KRAS were common in gastric-type IPNs as compared with others (P = .01 for both). SMAD4 was more frequently mutated in intestinal-type IPNs (P = .02). Pancreatobiliary-type IPNs (n = 14) exhibited frequent alterations in tumor suppressor genes including TP53, CDKN2A/B, and ARID2 (P = .04, P = .01 and P = .002, respectively). Of 6 IOPNs analyzed, 3 (50%) revealed ATP1B1-PRKACB fusion. ITPNs (n = 6) showed relatively few recurrent genetic aberrations. Follow-up information was available for 38 patients (median, 58.5 months). The ratio of disease-related deaths was higher for the cases with invasion (56% versus 10%).

CONCLUSIONS.—

Tumoral intraductal neoplasms of the bile ducts, similar to their counterparts in the pancreas, are morphologically and genetically heterogeneous.

Intraductal papillary neoplasms of the bile ducts-what can be seen with ultrasound?

Intraductal papillary neoplasm of the bile ducts is a rare tumor. Characteristic features include bile duct dilatation, cystic lesions with communication to the bile ducts, and intraluminal solid nodules arising from the bile duct wall. As in pancreatic intraductal papillary mucinous neoplasia, intestinal, pancreaticobiliary, gastric, and oncocytic types are described. Intraductal papillary neoplasm of the bile ducts has a high potential for malignancy, and patients should be surgically resected when possible. In this review, the complex imaging diagnosis is presented. The main focus is on contrast-enhanced ultrasound, an established method for many other indications whose potential on the biliary system should be better exploited. In the present article, typical contrast-enhanced ultrasound findings in intraductal papillary neoplasm of the bile ducts are demonstrated.

Intraductal papillary neoplasm of the bile duct: The new frontier of biliary pathology

Intraductal papillary neoplasms of the bile duct (IPNBs) represent a rare variant of biliary tumors characterized by a papillary growth within the bile duct lumen. Since their first description in 2001, several classifications have been proposed, mainly based on histopathological, radiological and clinical features, although no specific guidelines addressing their management have been developed. Bile duct neoplasms generally develop through a multistep process, involving different precursor pathways, ranging from the initial lesion, detectable only microscopically, i.e. biliary intraepithelial neoplasia, to the distinctive grades of IPNB until the final stage represented by invasive cholangiocarcinoma. Complex and advanced investigations, mainly relying on magnetic resonance imaging (MRI) and cholangioscopy, are required to reach a correct diagnosis and to define an adequate bile duct mapping, which supports proper treatment. The recently introduced subclassifications of types 1 and 2 highlight the histopathological and clinical aspects of IPNB, as well as their natural evolution with a particular focus on prognosis and survival. Aggressive surgical resection, including hepatectomy, pancreaticoduodenectomy or both, represents the treatment of choice, yielding optimal results in terms of survival, although several endoscopic approaches have been described. IPNBs are newly recognized preinvasive neoplasms of the bile duct with high malignant potential. The novel subclassification of types 1 and 2 defines the histological and clinical aspects, prognosis and survival. Diagnosis is mainly based on MRI and cholangioscopy. Surgical resection represents the mainstay of treatment, although endoscopic resection is currently applied to nonsurgically fit patients. New frontiers in genetic research have identified the processes underlying the carcinogenesis of IPNB, to identify targeted therapies.

Intraductal papillary neoplasm of the bile duct: review of updated clinicopathological and imaging characteristics

BACKGROUND

Intraductal papillary neoplasm of the bile duct (IPNB) is a relatively rare disease and is known as one of the premalignant lesions in the biliary tract. The concept of IPNB has changed through numerous studies and is still evolving. As a lesser studied clinical entity compared with its pancreatic counterpart, intraductal papillary mucinous neoplasm, IPNB has been described in many similar terms, including biliary papillomatosis, biliary intraductal papillary-mucinous neoplasm, and papillary cholangiocarcinoma. This is based on the diversity of histopathological spectrum of IPNB.

METHODS

This review investigated previous studies including original articles, case studies, and expert opinions. Recently, two types of IPNB (types 1 and 2) have been proposed and validated based on the content first established in the WHO 2010 criteria.

RESULTS

This review provides a comprehensive analysis of existing literature, summarizing the clinical, radiological, morphological, and pathological characteristics of IPNB.

CONCLUSION

Given the ongoing ambiguity and controversies surrounding IPNB, future research, including large population-based studies and molecular investigations, is essential to enhance understanding of this disease.

Reoperation for heterochronic intraductal papillary mucinous neoplasm of the pancreas after bile duct neoplasm resection: A case report

BACKGROUND

Intraductal papillary neoplasm of the bile duct (IPNB) and intraductal papillary mucinous neoplasm (IPMN) of the pancreas have similar pathological manifestations. However, they often develop separately and it is rare for both to occur together. Patients presenting with heterochronic IPMN after IPNB are prone to be misdiagnosed with tumor recurrence.

CASE SUMMARY

A 67-year-old male patient was admitted 8.5 years after IPNB carcinoma and 4 years after the discovery of a pancreatic tumor. A left hepatic bile duct tumor with distal bile duct dilatation was found 8.5 years ago by the computed tomography; therefore, a left hepatectomy was performed. The postoperative pathological diagnosis was malignant IPNB with negative cutting edge and pathological stage T1N0M0. Magnetic resonance imaging 4 years ago showed cystic lesions in the pancreatic head with pancreatic duct dilatation, and carcinoembryonic antigen continued to increase. Positron emission tomography showed a maximum standard uptake value of 11.8 in the soft tissue mass in the pancreatic head, and a malignant tumor was considered. Radical pancreatoduodenectomy was performed. Postoperative pathological diagnosis was pancreatic head IPMN with negative cutting edge, pancreaticobiliary type, stage T3N0M0. He was discharged 15 d after the operation. Follow-up for 6 mo showed no tumor recurrence, and quality of life was good.

CONCLUSION

IPNB and IPMN are precancerous lesions with similar pathological characteristics and require active surgery and long-term follow-up.

Intraductal papillary mucinous neoplasm of the biliary tract in the caudate lobe of the liver: a case report and literature review

An intraductal papillary mucinous neoplasm of the biliary tract (BT-IPMN) in the caudate lobe of the liver is a rare tumor originating from the bile duct. Approximately 40% of the intraductal papillary neoplasms of the biliary tract (IPNB) secrete mucus and can grow in the intrahepatic or extrahepatic bile ducts. A 65-year-old woman presented with recurrent episodes of right upper pain. She developed her first episode 8 years ago, which resolved spontaneously. The frequency of symptoms has increased in the last 2 years. She underwent laparoscopic hepatectomy and choledochal exploration and was pathologically diagnosed with a rare BT-IPMN of the caudate lobe after admission. Here, we review studies on IPNB cases and systematically describe the pathological type, diagnosis, and treatment of IPNB to provide a valuable reference for hepatobiliary surgeons in the diagnosis and treatment of this disease.

Intraductal papillary neoplasms of the bile duct: a European retrospective multicenter observational study (EUR-IPNB study)

BACKGROUND/PURPOSE

Intraductal papillary neoplasm of the bile duct (IPNB) is a rare disease in Western countries. The main aim of this study was to characterize current surgical strategies and outcomes in the mainly European participating centers.

METHODS

A multi-institutional retrospective series of patients with a diagnosis of IPNB undergoing surgery between 1 January 2010 and 31 December 2020 was gathered under the auspices of the European-African Hepato-Pancreato-Biliary Association. The textbook outcome (TO) was defined as a non-prolonged length of hospital stay plus the absence of any Clavien-Dindo grade at least III complications, readmission, or mortality within 90 postoperative days.

RESULTS

A total of 28 centers contributed 85 patients who underwent surgery for IPNB. The median age was 66 years (55-72), 49.4% were women, and 87.1% were Caucasian. Open surgery was performed in 72 patients (84.7%) and laparoscopic in 13 (15.3%). TO was achieved in 54.1% of patients, reaching 63.8% after liver resection and 32.0% after pancreas resection. Median overall survival was 5.72 years, with 5-year overall survival of 63% (95% CI: 50-82). Overall survival was better in patients with Charlson comorbidity score 4 or less versus more than 4 ( P =0.016), intrahepatic versus extrahepatic tumor ( P =0.027), single versus multiple tumors ( P =0.007), those who underwent hepatic versus pancreatic resection ( P =0.017), or achieved versus failed TO ( P =0.029). Multivariable Cox regression analysis showed that not achieving TO (HR: 4.20; 95% CI: 1.11-15.94; P =0.03) was an independent prognostic factor of poor overall survival.

CONCLUSIONS

Patients undergoing liver resection for IPNB were more likely to achieve a TO outcome than those requiring a pancreatic resection. Comorbidity, tumor location, and tumor multiplicity influenced overall survival. TO was an independent prognostic factor of overall survival.

Intraductal papillary neoplasm of the bile duct: Cytomorphologic and molecular features

BACKGROUND

Intraductal papillary neoplasm of the bile duct (IPNB) is a rare premalignant neoplasm that can progress to invasive adenocarcinoma. In this retrospective study, cases of IPNB were reviewed to examine cytomorphologic and molecular features.

METHODS

IPNB cytology cases with histopathologic confirmation were retrieved from the pathology archives. The cytomorphologic features such as cellularity, architecture, cell type, and cellular details were analyzed.

RESULTS

The cohort included 13 cases (six brushings, six fine-needle aspirations [FNA], and one combined brushing and FNA). The lesions involved common bile duct in nine cases (69%) and hepatic duct in four cases (31%). Original cytological diagnoses included adenocarcinoma (five, 38%), suspicious for adenocarcinoma (one, 8%), neoplasm (three, 23%), atypical (three, 23%), and reactive (one, 8%). The cytomorphologic features included moderate/high cellularity (12, 92%), papillary and/or complex papillary architecture (10, 77%), columnar cells (11, 85%), vacuolated cytoplasm (12, 92%), enlarged nuclei (13, 100%), and fine granular chromatin (12, 92%). Background mucin, necrosis and acute inflammation were seen in four (31%), four (31%), and two (15%) cases, respectively. KRAS testing was performed in nine cases with mutant KRAS found in five (56%).

CONCLUSIONS

Our study demonstrated that IPNB cytology specimens were relatively cellular with a wide spectrum of cytomorphology; however, most cases harbored adenocarcinoma or high-grade dysplasia. The characteristic cytomorphologic features included papillary/complex papillary clusters of columnar cells with vacuolated cytoplasm, enlarged nuclei, and fine granular chromatin in relatively cellular specimens. KRAS mutations identified may have potential diagnostic and therapeutic implications.

Clinicopathological Features and Long-Term Outcomes of Intraductal Papillary Neoplasms of the Bile Duct of the Liver: Single-Institution Experience with 146 Patients

BACKGROUND

Intraductal papillary neoplasm of the bile duct (IPNB) has a wide range of histopathology and intra- and extrahepatic tumor locations.

METHODS

This retrospective single-center study evaluated the clinicopathological features and long-term outcomes of 146 patients with IPNB of the liver (IPNB-L) who underwent hepatic resection between January 2002 and June 2019.

RESULTS

The 146 patients included 97 (66.4%) men and 49 (33.6%) women, of mean age 64.3 ± 8.0 years. Seventy-two (49.3%) patients were incidentally diagnosed, with no specific symptoms, and 18 (12.3%) were found to have hepatolithiasis. Sixty-one (41.8%) and two (1.4%) patients underwent concurrent bile duct resection and pancreaticoduodenectomy, respectively, and 130 (89.0%) underwent R0 resection. Low-grade and high-grade intraepithelial neoplasia, and invasive carcinoma were identified in 26 (17.8%), 50 (34.2%), and 70 (47.9%) patients, respectively. Five-year tumor recurrence and patient survival rates were 8.4% and 93.9%, respectively, in patients with high-grade neoplasia; and 41.5% and 72.3%, respectively, in patients with invasive carcinoma. CA19-9 > 37 U/mL and R1 resection were independent risk factors for tumor recurrence and reduced survival in patients with carcinoma. The combination of hypermetabolic fluorodeoxy-glucose-positron emission tomography (FDG-PET) or elevated CA19-9 showed a sensitivity of 91.8% and a specificity of 61.9% for the prediction of IPNB-L with high-grade neoplasia and carcinoma.

CONCLUSIONS

IPNB-L is a rare type of intrahepatic biliary neoplasm that can range histologically from benign disease to invasive carcinoma. Surgical curability is the most important prognostic factor, thus aggressive resection is highly recommended to achieve R0 resection.

Multicentric recurrence of intraductal papillary neoplasm of bile duct after spontaneous detachment of primary tumor: A case report

BACKGROUND

Intraductal papillary neoplasm of the bile duct (IPNB) rarely recurs in a multicentric manner. We encountered a patient with multiple recurrences of the gastric subtype of IPNB one year after spontaneous detachment of the primary tumor during peroral cholangioscopy (POCS).

CASE SUMMARY

A 68-year-old woman on maintenance hemodialysis because of lupus nephritis had several cardiovascular diseases and a pancreatic intraductal papillary mucinous neoplasm (IPMN). She was referred to our department for dilation of the common bile duct (CBD) and a tumor in the lumen, detected using ultrasonography. She had no complaints, and blood tests of hepatobiliary enzymes were normal. Magnetic resonance cholangiopancreatography (MRCP) showed a papillary tumor in the CBD with a filling defect detected using endoscopic retrograde cholangiography (ERC). Intraductal ultrasonography revealed a papillary tumor and stalk at the CBD. During POCS, the tumor spontaneously detached with its stalk into the CBD. Pathology showed low-intermediate nuclear atypia of the gastric subtype of IPNB. After 1 year, follow-up MRCP showed multiple tumors distributed from the left hepatic duct to the CBD. ERC and POCS showed multicentric tumors. She was alive without hepatobiliary symptoms at least two years after initial diagnosis of IPNB.

CONCLUSION

The patient experienced gastric subtype of IPNB without curative resection. Observation may be reasonable for patients with this subtype.

Peroral-cholangioscopy to plan surgery for protruding biliary lesions: report of four cases

Intraductal biliary lesions can involve the main hepatic confluence. Assessment of the extension of pedunculated biliary lesions during per-oral cholangioscopy (POCS) can optimize and personalize the surgical strategy. Four consecutive cases of pedunculated biliary lesions were analysed. Cholangioscopy was performed with a disposable single-operator cholangioscope. POSC was successfully performed in four patients (three female, mean age 50 years), showing involvement of the main biliary confluence in three of four pedunculated biliary lesions; direct biopsy sampling was diagnostic in two of three cases (in one patient, biopsy were not performed due to the smooth appearance of the intrabiliary lesion). No adverse events occurred after POCS. Surgery required excision of the main hepatic confluence in two of three cases (one patient was not resectable). POCS can diagnose intrabiliary extension of protruding biliary lesions, providing important information to plan the surgical intervention.

Mucin-producing Cystic Hepatobiliary Neoplasms: Updated Nomenclature and Clinical, Pathologic, and Imaging Features

Cystic hepatobiliary neoplasms with mucin-producing epithelium-mucinous cystic neoplasm of the liver (MCN) and intraductal papillary neoplasm of the bile duct (IPNB)-are rare and distinct entities that have unique clinical, pathologic, and imaging features. They are differentiated pathologically by the presence of subepithelial ovarian-like hypercellular stroma (OLS), which is the defining histopathologic feature of MCN. MCN is commonly a benign, large, solitary, symptomatic, multiloculated cystic mass without biliary communication that occurs in middle-aged women. On the other hand, IPNBs are a heterogeneous spectrum of tumors, which are commonly associated with invasive carcinoma, occur in older patients, and can be differentiated from MCN by communication with the biliary tree, intraductal masses, associated biliary ductal dilatation, and absent OLS. Understanding of these rare neoplasms has grown and evolved over time and continues to today, but uncertainty and controversy persist, related to the rarity of these tumors, relatively recent designation as separate entities, inherent clinicopathologic heterogeneity, overlapping imaging features, and the fact that many prior studies likely included MCN and cystic IPNB together as a single entity. Confusion regarding these neoplasms is evident by historical inconsistencies and nonstandardized nomenclature through the years. Awareness of these entities is important for the interpreting radiologist to suggest a particular diagnosis or generate a meaningful differential diagnosis in the appropriate setting, and is of particular significance as MCN and cystic IPNB have overlapping imaging features with other more common hepatobiliary cystic masses but have different management and prognosis. Online supplemental material is available for this article. Work of the U.S. Government published under an exclusive license with the RSNA.

Intrahepatic intraductal papillary cystic neoplasm of the bile duct: A case report

Introduction and importance

Intraductal papillary neoplasm of the bile duct (IPNB) is a tumour with a very low incidence in the Western world, characterised by a high risk of malignant transformation and unknown prognosis. It is a new entity which was adopted by the WHO in 2010 as a precursor lesion of cholangiocarcinoma. Intrahepatic bile duct is the most common site of origin for IPNB.

Case presentation

Hereby, we present a case of an asymptomatic 63- year-old man, referred to our department after routine ultrasonography showing a multifocal cystic lesion on the left hepatic lobe. Further screening modalities (CT, MRI abdo) confirmed a complex cystic liver lesion with atypical features. The patient underwent left hepatectomy. Histopathology showed a cystic type intrahepatic IPNB, which was completely resected (R0). The follow up in 2 yrs post-operation showed no signs of recurrence.

Clinical discussion

The diagnosis and management of IPNB remain challenging. A multimodality imaging approach is essential in order to diagnose IPNB, assess tumour location and extent and plan the optimal treatment strategy.

Conclusion

Complete surgical resection (R0) with close postoperative follow-up offers long-term survival.

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.

Lung metastases from intraductal papillary neoplasm of the bile duct: a case report

Background

Intraductal papillary neoplasm of the bile duct (IPNB) is considered a pre-cancerous biliary lesion and/or an early cancer lesion, although its classification remains unclear. The 2019 revised edition of the World Health Organization Classification of Tumors of the Digestive System proposed type 1 and type 2 as new classification categories, and meta-analyses and/or multi-center cohort studies are beginning to be reported. However, treatment for IPNB recurrence and metastasis remains unclear.

Case presentation

A 60-year-old man who was referred to our hospital after a suspected liver tumor was diagnosed using abdominal ultrasonography. Imaging findings revealed an irregularly shaped tumor in segment 5 (S5) of the liver (size 20 mm). The S5 lesion was suspected as IPNB, and segmentectomy was performed. The pathological findings revealed invasive carcinoma derived from IPNB, and immunohistochemistry revealed positive expression of MUC1, MUC5AC, and MUC6, but negative expression of CDX2 and MUC2. At 9 months after the surgery, computed tomography revealed a tumor in the right bile duct, which was diagnosed as liver recurrence of IPNB, and right hepatectomy was performed. The histopathological findings were the same as for the first resected specimen (i.e., IPNB). At 45 months after the second surgery, computed tomography revealed nodules in both lungs, which were diagnosed as lung metastases from IPNB and resected in two separate procedures. The pathological findings were metastatic carcinoma from IPNB for both lung lesions. The patient is currently alive and undergoing adjuvant chemotherapy (S-1), which was initiated 64 months after the first resection and 12 months after resection of the lung metastases.

Conclusion

We encountered a rare case of lung metastases from IPNB, which were diagnosed immunohistologically. Because IPNB is generally a slow-growing tumor, resection may be feasible for IPNB recurrence and/or metastasis, which may be detected during long-term follow-up. Thus, even if resection is performed for primary IPNB, additional surgical treatment may be feasible in this setting.

Clinicopathologic analysis of intraductal papillary neoplasm of bile duct: Korean multicenter cohort study

BACKGROUND

IPNB is very rare disease and most previous studies on IPNB were case series with a small number due to low incidence. The aim of this study is to validate previously known clinicopathologic features of intraductal papillary neoplasm of bile duct (IPNB) based on the first largest multicenter cohort.

METHODS

Among 587 patients previously diagnosed with IPNB and similar diseases from each center in Korea, 387 were included in this study after central pathologic review. We also reviewed all preoperative image data.

RESULTS

Of 387 patients, 176 (45.5%) had invasive carcinoma and 21 (6.0%) lymph node metastasis. The 5-year overall survival was 80.9% for all patients, 88.8% for IPNB with mucosal dysplasia, and 70.5% for IPNB with invasive carcinoma. According to the "Jang & Kim's modified anatomical classification," 265 (68.5%) were intrahepatic, 103 (26.6%) extrahepatic, and 16 (4.1%) diffuse type. Multivariate analysis revealed that tumor invasiveness was a unique predictor for survival analysis. (p = 0.047 [hazard ratio = 2.116, 95% confidence interval 1.010-4.433]).

CONCLUSIONS

This is the first Korean multicenter study on IPNB through central pathologic and radiologic review process. Although IPNB showed good long-term prognosis, relatively aggressive features were also found in invasive carcinoma and extrahepatic/diffuse type.

Cystic intraductal papillary neoplasms with infiltrating carcinoma of the intrahepatic bile duct: A case report

INTRODUCTION

Intraductal papillary neoplasms of the bile duct (IPNB) is a kind of rare disorder with low incidence but high misdiagnosis due to untypical symptoms and non-specific laboratory indicators. Herein, we report a case of cystic type IPNB with infiltrating carcinoma of the intrahepatic bile duct presented as a single giant cystic mass of the liver.

PATIENT CONCERNS

A 51-year-old woman was admitted due to right upper abdominal discomfort for 10 months. Physical examination indicated no specific finding. Laboratory tests showed that serum total bilirubin and carcinoembryonic antigen level was mildly elevated. Ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI) of abdomen indicated a giant lobulated cystic lesion involving the left, right and the caudate lobes of liver. There were multiple small nodules of different sizes with papillary or coral reef-like pattern protruding into the cystic lumen from the inner wall.

DIAGNOSIS

The patient was diagnosed as malignant tumors of intrahepatic bile duct.

INTERVENTIONS

She received radical resection of the lesion by hepatectomy.

OUTCOMES

The postoperative pathological examination revealed an IPNB with infiltrating carcinoma of the intrahepatic bile duct. This patient had an uneventful postoperative recovery and was discharged on day 21 post-surgery. Until 35 months after surgery, there is no recurrence or metastasis.

CONCLUSION

The CT and MRI can show certain morphologic features including the segmental cystic dilatation of intrahepatic bile ducts and the pathological details of papillary tumors inside the lesion. Cystic IPNB with infiltrating carcinoma of the intrahepatic bile duct can be treated with surgery.

Precursors to Cholangiocarcinoma

Cancers of the biliary tract include intra- and extrahepatic cholangiocarcinomas and gallbladder cancer. Biliary tract cancers are diseases with unfavorable prognoses. In recent years, several lesions have been described as precursors that precede biliary cancers. They include flat and microscopic lesions known as biliary intraepithelial neoplasia, macroscopic and tumor-forming intraductal papillary biliary neoplasia, intraductal tubular neoplasia, and mucinous cystic neoplasm of the bile duct. These conditions are rarely diagnosed, while their natural history and progression to cancer have yet to be adequately characterized. This review examines the epidemiology, pathology, molecular biology, diagnosis, and therapy of these various precursors. Further research is required if we are to better understand this evolving field and improve the prevention and early detection of bile duct cancer.

Long-term growth of intrahepatic papillary neoplasms: A case report

BACKGROUND

Intraductal papillary neoplasm of the bile duct (IPNB) is a type of tumor that presents in the intra- or extrahepatic bile ducts. Cystic-type intrahepatic IPNB often mimics simple liver cysts, making the diagnosis difficult. Because the growth of IPNB is slow, careful follow-up and timely therapeutic intervention is recommended. There are few reports with a follow-up period longer than a decade; thus, we report the case of a patient with an IPNB that grew for over 13 years.

CASE SUMMARY

A 65-year-old man was diagnosed, 13 years prior with a cystic hepatic tumor with abnormal imaging findings. The targeted tumor biopsy results showed no malignancy. Biannual follow-up examinations were performed because of the potential for malignancy. The cystic lesions showed gradual enlargement over 11 years and a 4 mm papillary proliferation appeared on the cyst wall, which is compatible with IPNB. The tumor was observed for another 2 years because of the patient’s wishes. The imaging findings showed enlargement to 8 mm and a new 9 mm papillary proliferation of the cystic tumor. Contrast-enhanced ultrasonography showed hyperenhancement during the arterial phase in both cyst walls, indicating intraductal tumor progression in both tumors. Thus, liver segment 8 subsegmentectomy was performed. The pathological findings indicated that the tumors contained mucin, and high-grade atypia was observed in the papillary lesions, showing IPNB.

CONCLUSION

The development of IPNB should be monitored in patients with cystic lesions and ultrasonography are useful tool for the evaluation.

Mucins: the Old, the New and the Promising Factors in Hepatobiliary Carcinogenesis

Mucins are large O-glycoproteins with high carbohydrate content and marked diversity in both the apoprotein and the oligosaccharide moieties. All three mucin types, trans-membrane (e.g., MUC1, MUC4, MUC16), secreted (gel-forming) (e.g., MUC2, MUC5AC, MUC6) and soluble (non-gel-forming) (e.g., MUC7, MUC8, MUC9, MUC20), are critical in maintaining cellular functions, particularly those of epithelial surfaces. Their aberrant expression and/or altered subcellular localization is a factor of tumour growth and apoptosis induced by oxidative stress and several anti-cancer agents. Abnormal expression of mucins was observed in human carcinomas that arise in various gastrointestinal organs. It was widely believed that hepatocellular carcinoma (HCC) does not produce mucins, whereas cholangiocarcinoma (CC) or combined HCC-CC may produce these glycoproteins. However, a growing number of reports shows that mucins can be produced by HCC cells that do not exhibit or are yet to undergo, morphological differentiation to biliary phenotypes. Evaluation of mucin expression levels in precursors and early lesions of CC, as well as other types of primary liver cancer (PLC), conducted in in vitro and in vivo models, allowed to discover the mechanisms of their action, as well as their participation in the most important signalling pathways of liver cystogenesis and carcinogenesis. Analysis of mucin expression in PLC has both basic research and clinical value. Mucins may act as oncogenes and tumour-promoting (e.g., MUC1, MUC13), and/or tumour-suppressing factors (e.g., MUC15). Given their role in promoting PLC progression, both classic (MUC1, MUC2, MUC4, MUC5AC, MUC6) and currently tested mucins (e.g., MUC13, MUC15, MUC16) have been proposed to be important diagnostic and prognostic markers. The purpose of this review was to summarize and update the role of classic and currently tested mucins in pathogenesis of PLC, with explaining the mechanisms of their action in HCC carcinogenesis. It also focuses on determination of the diagnostic and prognostic role of these glycoproteins in PLC, especially focusing on HCC, CC and other hepatic tumours with- and without biliary differentiation.