GNAS codon 201 mutations are uncommon in intraductal papillary neoplasms of the bile duct

Dysplasia and Early Carcinoma of the Gallbladder and Bile Ducts: Terminology, Classification, and Significance

Most precursor lesions and early cancerous changes in the gallbladder and bile ducts present as clinically/grossly inapparent lesions. Low-grade dysplasia is difficult to define and clinically inconsequential by itself; however, extra sampling is required to exclude accompanying significant lesions. For high-grade dysplasia ('carcinoma in situ'), a complete sampling is necessary to rule out invasion. Tumoral intramucosal neoplasms (ie, intracholecystic and intraductal neoplasia) form radiologically/grossly visible masses, and they account for (present in the background of) about 5% to 10% of invasive cancers of the region. These reveal a spectrum of papilla/tubule formation, cell lineages, and dysplastic transformation. Some subtypes such as intracholecystic tubular non-mucinous neoplasm of the gallbladder (almost never invasive) and intraductal oncocytic or intraductal tubulopapillary neoplasms of the bile ducts (may have a protracted clinical course even when invasive) are to be noted separately. Other types of intracholecystic/intraductal neoplasia have a high frequency of invasive carcinoma and progressive behavior, which often culminates in mortality.

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.

Biliary Tract Cancer: Molecular Biology of Precursor Lesions

Biliary tract cancer is a devastating malignancy of the bile ducts and gallbladder with a dismal prognosis. The study of precancerous lesions has received considerable attention and led to a histopathological classification which, in some respects, remains an evolving field. Consequently, increasing efforts have been devoted to characterizing the molecular pathogenesis of the precursor lesions, with the aim of better understanding the mechanisms of tumor progression, and with the ultimate goal of meeting the challenges of early diagnosis and treatment. This review delves into the molecular mechanisms that initiate and promote the development of precursor lesions of intra- and extrahepatic cholangiocarcinoma and of gallbladder carcinoma. It addresses the genomic, epigenomic, and transcriptomic landscape of these precursors and provides an overview of animal and organoid models used to study them. In conclusion, this review summarizes the known molecular features of precancerous lesions in biliary tract cancer and highlights our fragmentary knowledge of the molecular pathogenesis of tumor initiation.

Design and evaluation of a sustainable entropy-weighted and VIKOR-based method for offshore oil collecting

With the expansion of marine oil exploitation, offshore oil leakage has become an urgent problem that cannot be ignored in marine ecological protection. To address the problem, this paper proposes a comprehensive design and evaluation approach aiming at the design of offshore oil collection. This approach combines the entropy weight and VIKOR method with three principles of sustainable design. Specifically, to establish the evaluation model, this paper transforms these principles of sustainability into three aspects of practicality, economy, and environmental protection, thus constructing a multi-level evaluation index system. Subsequently, entropy weights are then used to decline the one's own element in the decision maker's weights. Besides this, the VIKOR method is applied to acquire the optimal ranking of design alternatives for offshore oil collection to choose the optimal product design strategy. According to the obtained experimental results, the proposed design method combining the entropy weight and the VIKOR method is feasible and reasonable. To be exact, it improves the comprehensive index of the product in the design concept stage by over 20%, and it effectively optimizes the resource allocation of the design process.

Natural history of intracholecystic papillary neoplasm (ICPN): a rare case of ICPN whose natural history was closely followed by ultrasound

The natural history of intracholecystic papillary neoplasm (ICPN), especially the speed of growth from small benign to a carcinomatous lesion, is quite unrevealed. Here, we report an extremely rare case of ICPN, in which the papillary lesion was observed transforming from small and benign to malignant using abdominal ultrasound (AUS) over 2 years during routine health checks. A 44-year-old man underwent a routine health check-up. The initial AUS showed a small sessile polyp in the gallbladder, which enlarged slightly at the next AUS, a year later. In the third year, the polypoid lesion enlarged markedly, with a maximum diameter of 10 × 9 × 7 mm. Therefore, a laparoscopic cholecystectomy was performed. Microscopically, the 10 mm tumor had intracytoplasmic mucus, and a clear cytoplasm compatible with gastric-type features. Immunohistochemical analysis showed positive staining of atypical cells for MUC6 and PAS. These findings led to the diagnosis of ICPN with high-grade intraepithelial neoplasia of the gastric type. In conclusion, sessile polyps with rapid growth might be a crucial finding in the early stage of ICPN.

Whole-genome copy number and immunohistochemical analyses on surgically resected intracholecystic papillary neoplasms

Intracholecystic papillary neoplasms are newly defined precancerous lesions. According to Classification of the World Health Organization, they have four histological morphologies, which are biliary, gastric, intestinal, and oncocytic. This study evaluated 17 patients with resected intracholecystic papillary neoplasms in terms of histological, immunohistochemical, and copy number variation (CNV). The histological subtypes included 5 cases of low-grade (5 gastric) and 12 cases of high-grade (6 gastric and 6 biliary) neoplasms. Most cases showed high expression of MUC1, MUC5AC, and CK7, moderate expression of MUC6 and Ki-67, and low expression of CK20, MUC2, and CDX2. The CNV profile identified gain of 7q in 12%, and loss of 1p (18%), 5q (29%), 9p (35%), 12p (17%), 17p (24%), and 19p (18%). No CNVs were observed in low-grade neoplasms, whereas high-grade ones had increasing abnormalities. β-catenin was often expressed in the nucleus of neoplasms with gastric morphology, suggesting the involvement of the Wnt/β-catenin pathway. However, it was not expressed among those with biliary morphology, which instead exhibited high p53 expression. Neoplasms with biliary morphology showed more CNV changes (9p, 17p, 19p losses). Distinct immunological and CNV patterns were seen in both morphologies, suggesting differences in their pathogenesis. More CNVs accumulated with tumor progression.

Reappraisal of pathological features of intraductal papillary neoplasm of bile duct with respect to the type 1 and 2 subclassifications

The pathological spectrum of intraductal papillary neoplasm of bile duct (IPNB) remains to be clarified. A total of 186 IPNBs were pathologically examined using the type 1 and 2 subclassifications proposed by Japanese and Korean biliary pathologists incorporating a two-tiered grading system (low-grade and high-grade dysplasia), with reference to four subtypes (intestinal [i], gastric [g], pancreatobiliary [pb], and concocytic [o] subtype). IPNBs were classifiable into type 1 composed of low-grade dysplasia and 'high-grade dysplasia with regular structures' (69 IPNBs), and type 2 of 'high grade dysplasia with irregular structures and complicated lesions' (117 IPNBs). Type 1 was more common in the intrahepatic bile duct (78%), whereas type 2 was frequently located in the extrahepatic bile duct (58%). Mucin hypersecretion was more common in type 1 (61%) than in type 2 (37%). IPNBs were classifiable into the four subtypes: 86 iPNBs, 40 gIPNBs, 31 pbIPNBs, and 29 oIPNBs. The four subtypes were histologically evaluable with reference to the type 1 and 2 subclassifications. iIPNB and pbIPNBs were frequently classified as type 2, whereas types 1 and 2 were observed at similar rates in gIPNB and oIPNB. Stromal invasion was almost absent in type 1, irrespective of subtype, but was found in 66 of 117 type 2 IPNBs (P < .01), and postoperative outcome was favorable in IPNBs without invasion compared with IPNBs with invasion (P < .05). The type 1 and 2 subclassifications with reference to the four subtypes may provide useful information for understanding IPNB.

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.

Biliary intraductal tubule-forming neoplasm: a whole exome sequencing study of MUC5AC-positive and -negative cases

AIMS

Biliary intraductal tubular neoplasms that are non-mucinous and negative for mucin 5AC (MUC5AC) are called intraductal tubulopapillary neoplasms (ITPNs). Intraductal tubular neoplasms with mucinous cytoplasm and MUC5AC positivity also occur and their nature remains unclear, although some pathologists may classify these as 'intraductal papillary neoplasms of the bile duct (IPNBs) of gastric type'. This study aimed to elucidate genetic features of biliary intraductal tubular neoplasms.

METHODS AND RESULTS

Six resected cases of biliary intraductal neoplasm with >70% tubular configuration were characterised by clinicopathological examination and whole exome sequencing, and the findings obtained were compared between MUC5AC-negative (n = 2) and -positive cases (n = 4). The intraductal tumours consisted of the pancreatobiliary-type epithelium with high-grade dysplasia arranged in back-to-back tubules. Both of the two MUC5AC-negative cases were non-invasive neoplasms and developed in the liver, whereas all MUC5AC-positive cases had invasive carcinoma and were present in the intrahepatic (n = 2), perihilar (n = 1) and distal bile ducts (n = 1). In an exome-sequencing study, MUC5AC-negative cases harboured mutations in CTNNB1, SF3B1, BAP1 and BRCA1 (one case each). KRAS mutations were observed in three of four MUC5AC-positive cases (75%) but none of the MUC5AC-negative neoplasms. Compared to published data, known driver genes of other intraductal neoplasms of the pancreatobiliary system (e.g. APC, CTNNB1, STK11, GNAS and PIK3CA) were wild-type in all but one MUC5AC-negative case with CTNNB1 mutation. Chromatin modifiers (ARID1A, BAP1 and KMT2C) were also altered in MUC5AC-positive cases, similar to usual cholangiocarcinomas.

CONCLUSIONS

This exome-sequencing study suggested that MUC5AC-negative biliary ITPNs are genetically distinct from pancreatic ITPNs and IPNBs. They may also biologically differ from MUC5AC-positive tubular neoplasms despite morphological resemblance.

Genetically engineered animal models of biliary tract cancers

PURPOSE OF REVIEW

Biliary tract cancers which include intrahepatic and extrahepatic cholangiocarcinomas and gallbladder cancer, are characterized by poor outcome. Therefore, identifying the molecular mechanisms of the disease has become a priority. However, such identification has to cope with extreme heterogeneity of the disease, which results from the variable anatomical location, the numerous cell types of origin and the high number of known genetic alterations.

RECENT FINDINGS

Animal models can develop invasive and metastatic tumours that recapitulate as faithfully as possible the molecular features of the human tumours. To generate animal models of cholangiocarcinoma, investigators resorted to the administration of carcinogens, induction of cholestasis, grafting of tumour cells and induction of genetic modifications.

SUMMARY

Here, we summarize the currently available genetically engineered animal models, and focus on mice and zebrafish. The experimental strategies that were selected to induce cholangiocarcinoma in a time-controlled and cell-type-specific manner are critically examined. We discuss their strengths and limitations while considering their relevance to human pathophysiology.

Recurrent Rearrangements in PRKACA and PRKACB in Intraductal Oncocytic Papillary Neoplasms of the Pancreas and Bile Duct

BACKGROUND & AIMS

Intraductal oncocytic papillary neoplasms (IOPNs) of the pancreas and bile duct contain epithelial cells with numerous, large mitochondria and are cystic precursors to pancreatic ductal adenocarcinoma (PDAC) and cholangiocarcinoma (CCA), respectively. However, IOPNs do not have the genomic alterations found in other pancreatobiliary neoplasms. In fact, no recurrent genomic alterations have been described in IOPNs. PDACs without activating mutations in KRAS contain gene rearrangements, so we investigated whether IOPNs have recurrent fusions in genes.

METHODS

We analyzed 20 resected pancreatic IOPNs and 3 resected biliary IOPNs using a broad RNA-based targeted sequencing panel to detect cancer-related fusion genes. Four invasive PDACs and 2 intrahepatic CCAs from the same patients as the IOPNs, were also available for analysis. Samples of pancreatic cyst fluid (n = 5, collected before surgery) and bile duct brushings (n = 2) were analyzed for translocations. For comparison, we analyzed pancreatobiliary lesions from 126 patients without IOPN (controls).

RESULTS

All IOPNs evaluated were found to have recurring fusions of ATP1B1-PRKACB (n = 13), DNAJB1-PRKACA (n = 6), or ATP1B1-PRKACA (n = 4). These fusions also were found in corresponding invasive PDACs and intrahepatic CCAs, as well as in matched pancreatic cyst fluid and bile duct brushings. These gene rearrangements were absent from all 126 control pancreatobiliary lesions.

CONCLUSIONS

We identified fusions in PRKACA and PRKACB genes in pancreatic and biliary IOPNs, as well as in PDACs and pancreatic cyst fluid and bile duct cells from the same patients. We did not identify these gene fusions in 126 control pancreatobiliary lesions. These fusions might be used to identify patients at risk for IOPNs and their associated invasive carcinomas.

Intracholecystic papillary neoplasm of the gallbladder protruding into the common bile duct: A case report

The current study indicates the case of intracholecystic papillary neoplasm (ICPN) protruding into the common bile duct (CBD) without superficial spread. A 58-year-old woman presented to hospital with a fever that lasted for three days. Laboratory tests revealed elevated hepatobiliary enzyme levels. CT, MRI and endoscopic ultrasonography revealed a polypoid, papillary tumor inside the gallbladder cavity, which also extended to the CBD. On peroral cholangioscopy, a papillary tumor with mucin production was found at the middle bile duct. Biliary biopsy and bile cytology indicated adenocarcinoma. Based on a diagnosis of ICPN extending to the CBD, the patient underwent subtotal stomach-preserving pancreaticoduodenectomy and gallbladder bed resection. However, pathological examination revealed that the ICPN was confined to the gallbladder and cystic duct, whereas the CBD was tumor-free. The present case indicates that when ICPN increases in size, it may protrude into the CBD due to an increased intracholecystic pressure, which increases the risk of overestimation of tumor extension and may result in unnecessary additional bile duct resection.

Recurrent Mutations in APC and CTNNB1 and Activated Wnt/β-catenin Signaling in Intraductal Papillary Neoplasms of the Bile Duct: A Whole Exome Sequencing Study

This study aimed to elucidate the genetic landscape of biliary papillary neoplasms. Of 28 cases examined, 7 underwent whole exome sequencing, while the remaining 21 were used for validation studies with targeted sequencing. In the whole exome sequencing study, 4/7 cases had mutations in either APC or CTNNB1, both of which belong to the Wnt/β-catenin pathway. Somatic mutations were also identified in genes involved in RAS signaling (KRAS, BRAF), a cell cycle regulator (CDC27), histone methyltransferase (KMT2C, KMT2D), and DNA mismatch repair (MSH3, MSH6, PMS1). Combined with discovery and validation cohorts, mutations in APC or CTNNB1 were observed in 6/28 subjects (21%) and were mutually exclusive. When the cases were classified into intraductal papillary neoplasms of the bile duct (IPNBs, n=14) and papillary cholangiocarcinomas (n=14) based on the recently proposed classification criteria, mutations in APC and CTNNB1 appeared to be entirely restricted to IPNBs with 6/14 cases (43%) harboring mutations in either gene. These genetic alterations were detected across the 3 nonintestinal histologic types. In immunohistochemistry, the aberrant cytoplasmic and/or nuclear expression of β-catenin was found in not only 5/6 IPNBs with APC or CTNNB1 mutations, but also 6/8 cases with wild-type APC and CTNNB1 (total 79%). In addition, APC and CTNNB1 alterations were exceptional in nonpapillary cholangiocarcinomas (n=29) with a single case harboring CTNNB1 mutation (3%). This study demonstrated recurrent mutations in APC and CTNNB1 in nonintestinal-type IPNBs, suggesting that activation of the Wnt/β-catenin signaling pathway is relevant to the development and progression of IPNBs.

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.

Clinical and Radiographic Gastrointestinal Abnormalities in McCune-Albright Syndrome

Context

McCune-Albright syndrome (MAS) is a rare disorder characterized by fibrous dysplasia of bone, café-au-lait macules, and hyperfunctioning endocrinopathies. It arises from somatic gain-of-function mutations in GNAS, which encodes the cAMP-regulating protein Gαs. Somatic GNAS mutations have been reported in intraductal papillary mucinous neoplasms (IPMNs) and various gastrointestinal (GI) tumors. The clinical spectrum and prevalence of MAS-associated GI disease is not well established.

Objective

Define the spectrum and prevalence of MAS-associated GI pathology in a large cohort of patients with MAS.

Design

Cross-sectional study.

Setting

National Institutes of Health Clinical Center and The Johns Hopkins Hospital.

Methods

Fifty-four consecutive subjects with MAS (28 males; age range, 7 to 67 years) were screened with magnetic resonance cholangiopancreatography (MRCP).

Results

Thirty of 54 subjects (56%) had radiographic GI abnormalities. Twenty-five (46%) of the screened subjects had IPMNs (mean age of 35.1 years). Fourteen of the 25 had IPMNs alone, and 11 had IPMNs and abnormal hepatobiliary imaging. The 30 patients with MAS-associated GI pathology had a higher prevalence of acute pancreatitis, diabetes mellitus, and skeletal disease burden of fibrous dysplasia than patients without GI disease.

Conclusions

A broad spectrum of GI pathology is associated with MAS. IPMNs are common and occur at a younger age than in the general population. Patients with MAS should be considered for screening with a focused GI history and baseline MRCP. Further determination of the natural history and malignant potential of IPMNs in MAS is needed.

Intraductal papillary neoplasm of the bile duct: a single-center retrospective study

Objective Intraductal papillary neoplasm of the bile duct (IPNB) has been increasingly recognized and reported. However, its clinical features are still controversial because of its low incidence. In the present study, we investigated the characteristics of IPNB. Methods In total, 28 patients with IPNB were treated at our institution from January 2000 to December 2016. Clinical data were collected and a retrospective accurate database was constructed. Demographic characteristics, perioperative management, and prognosis were retrospectively analyzed. Results Abdominal discomfort was the most common symptom. Preoperative imaging revealed biliary tract dilatation in 23 patients. Left lateral or left hepatic lobectomy was the most frequently performed surgical procedure. Histological analysis revealed malignancy in 17 patients. Eighty-eight lymph nodes were swept from the patients with malignant disease, but only three were metastatic. Twenty-one patients were followed up for 3 to 60 months (mean, 29.4 ± 18.2 months). Seven patients died during the follow-up period. Patients with benign tumors had significantly greater disease-free survival. Conclusions IPNB is a rare biliary disease that occurs mainly in patients of advanced age. The most common symptom is abdominal discomfort. Lymphatic metastasis is uncommon. Patients with benign tumors may have a better prognosis than those with malignant tumors.

The curious case of Gαs gain-of-function in neoplasia

BACKGROUND

Mutations activating the α subunit of heterotrimeric Gs protein are associated with a number of highly specific pathological molecular phenotypes. One of the best characterized is the McCune Albright syndrome. The disease presents with an increased incidence of neoplasias in specific tissues.

MAIN BODY

A similar repertoire of neoplasms can develop whether mutations occur spontaneously in somatic tissues during fetal development or after birth. Glands are the most "permissive" tissues, recently found to include the entire gastrointestinal tract. High frequency of activating Gαs mutations is associated with precise diagnoses (e.g., IPMN, Pyloric gland adenoma, pituitary toxic adenoma). Typically, most neoplastic lesions, from thyroid to pancreas, remain well differentiated but may be a precursor to aggressive cancer.

CONCLUSIONS

Here we propose the possibility that gain-of-function mutations of Gαs interfere with signals in the microenvironment of permissive tissues and lead to a transversal neoplastic phenotype.

KRAS mutation and immunohistochemical profile in intraductal papillary neoplasm of the intrahepatic bile ducts

Intraductal papillary neoplasm of bile duct (IPNB) is characterized by a spectrum of diseases ranging from low-grade intraepithelial neoplasia to invasive carcinoma. In the present study, we aimed to investigate immunophenotypic features and KRAS mutations in relation to pathological subtypes and grades in Chinese patients with IPNBs. A total of 46 patients with IPNBs and 11 invasive adenocarcinomas arising in IPNBs (invasive IPNBs) were enrolled and clinicopathological data were analyzed. It was found that CK7 was expressed in 42 of the 46 neoplastic lesions. HepPar1 was expressed in 11 of the 46 noninvasive IPNBs, but not in invasive IPNBs. Additionally, CK19 was frequently expressed in both noninvasive IPNBs and invasive IPNBs. The intestinal-type IPNBs had a significantly higher percentage of MUC2 expression relative to the pancreaticobiliary (P=0.015) and gastric-type IPNBs (P<0.001). High-grade IPNBs and invasive IPNBs showed increased expression of cyclin D1, Ki-67, p53, mCEA, and CA19-9. The rate of KRAS mutation was significantly higher in high-grade IPNBs (P=0.001) and invasive IPNBs (P=0.006) than that in low- to intermediate-grade IPNBs. Additionally, KRAS mutation was significantly associated with tumor size, and Ki-67 expression. In conclusion, the expression of cyclin D, Ki-67, p53, mCEA and CA19-9 and KRAS mutation status are significantly correlated with histological grades of IPNBs.

Clinicopathological features of intraductal papillary neoplasms of the bile duct: a comparison with intraductal papillary mucinous neoplasm of the pancreas with reference to subtypes

Intraductal papillary epithelial neoplasms of the pancreatobiliary system (intraductal papillary neoplasm of the bile duct (IPNB) and intraductal papillary mucinous neoplasm (IPMN)) seem to share many clinicopathological features; however, IPNB has not been fully characterized. In order to understand the clinicopathological/immunohistochemical features of IPNB better, we compared 52 cases of IPNB with 42 cases of IPMNs with mural nodules. The IPNB cases were divided into two groups according to their histological similarity and according to five key histological findings. All IPNB and IPMN cases mainly affected middle-aged to elderly people, predominantly men. Mucin hypersecretion was less frequent in IPNB compared to IPMN. Group 2 IPNB more frequently had a higher histopathological grade and more extensive stromal invasion than IPMN. Group 1 IPNB and IPMN were further classified into four subtypes (gastric, intestinal, pancreatobiliary, and oncocytic). Although each subtype of IPNB and IPMN showed similar histology, the immunohistochemical results were different. The gastric type of IPNB was less frequently positive for CDX2, and intestinal IPNB was more frequently positive for MUC1 and less frequently positive for MUC2, MUC5AC, and CDX2 compared to each subtype of IPMN, respectively. In conclusion, IPNB and IPMN have some clinicopathological features in common, but mucin hypersecretion was less frequent both in IPNBs than in IPMN. Group 2 IPNB differed from IPMN in several parameters of tumor aggressiveness. Additional clinicopathological and molecular studies should be performed with respect to the subtypes of IPNB and IPMN.

Comparative clinicopathological study of biliary intraductal papillary neoplasms and papillary cholangiocarcinomas

AIMS

The aim of this study was to achieve a better definition of intraductal papillary neoplasms of the bile duct (IPNBs).

METHODS AND RESULTS

Biliary tumours that showed predominantly intraductal papillary growth were provisionally classified as IPNBs (n = 25) and papillary cholangiocarcinomas (n = 27). IPNB was defined as a neoplasm that is confined to the epithelium or is regularly arranged in a high-papillary architecture along thin fibrovascular stalks, whereas the term 'papillary cholangiocarcinoma' was used for tumours with more complex papillary structures (e.g. irregular papillary branching or mixed with solid-tubular growth). In our consecutive cohort of biliary neoplasms, 5% were classified as IPNBs, and 10% as papillary cholangiocarcinomas. IPNBs differed from papillary cholangiocarcinomas by less advanced invasion, gross mucin overproduction (72% versus 7%), and their prevalent location (84% of IPNBs in intrahepatic/hilar ducts; 70% of papillary cholangiocarcinomas in extrahepatic ducts). Gastric-type and oncocytic-type tumours were only detected in IPNBs. Expression of mucin core proteins and cytokeratin 20 significantly differed between the two groups. KRAS and GNAS were wild-type genotypes in all but one case of KRAS-mutated IPNB. Patients with IPNB had better recurrence-free survival than those with papillary cholangiocarcinoma (P = 0.007). In multivariate analysis, in which several other prognostic factors (e.g. stromal invasion and lymph node metastasis) were applied, the classification of the two papillary tumours was an independent prognostic factor (P = 0.040).

CONCLUSIONS

Given the significant contrast in clinicopathological features between IPNBs and papillary cholangiocarcinomas, it may be more appropriate to use the diagnostic term 'IPNB' for selected tumours that show regular papillary growth, separately from papillary cholangiocarcinomas.

Systematic Review and Meta-analysis of Current Experience in Treating IPNB: Clinical and Pathological Correlates

OBJECTIVE

To systematically review studies reporting clinicopathological features of intraductal papillary neoplasm of the bile duct (IPNB) to provide evidence-based guidance for management.

BACKGROUND

IPNB is a rare tumor type. Management decisions are currently based upon anecdotal evidence and small case series. To data, there has been no systematic review of IPNB literature.

METHODS

MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched and data were extracted from relevant studies. Meta-analysis was used to pool study estimates. Evidence of association was determined by comparing pooled crude odds ratios (OR) derived from abstracted data.

RESULTS

Fifty-seven retrospective case series were included. At least 43% of 476 specimens contained invasive disease. Invasive tumors were found at significantly higher frequency in pancreaticobiliary than intestinal, gastric or oncocytic-type IPNB [pooled OR 2.5, 95% confidence interval (CI) 1.5-4.2, P < 0.001]. A significantly higher proportion of pancreaticobiliary tumors compared with intestinal tumors expressed MUC-1 [86.4% (95% CI 75.1%-94.7%) vs 13.2% (95% CI 4.6%-25.2%), respectively P < 0.001]. IPNB identified in centers from Asia were more likely to be intrahepatic and were less frequently invasive compared with those from Western centers. Pooled estimates of absolute survival after IPNB resection were 96% (95% CI 93%-99%) at 1 year, 79% (95% CI 69%-88%) at 3 years, and 65% (95% CI 46%-76%) at 5 years.

CONCLUSIONS

Early surgery is advisable for radiologically suspected IPNB as it is frequently invasive. The pathobiology of IPNB demonstrates geographic variation. Pancreaticobiliary IPNB expresses MUC1 and is more frequently associated with invasive disease than other IPNB subtypes.

Cholangiocarcinoma with intraductal tubular growth pattern versus intraductal papillary growth pattern

Intraductal neoplasms of the bile duct are macroscopically characterized by exophytic or polypoid growth patterns and have a favorable prognosis. Although some tumors with a predominantly tubular microscopic pattern have been reported, they have not been well characterized clinicopathologically. The purpose of the present study was to compare the newly recognized cholangiocarcinoma with an intraductal tubular growth pattern and cholangiocarcinoma with an intraductal papillary growth pattern and to investigate the pathological and prognostic significance of the former. This study analyzed 161 patients with tumors with exophytic or polypoid growth patterns from a large series of 733 cholangiocarcinoma cases surgically resected from January 1998 to May 2013. The study patients were divided into two groups: those whose tumors showed a predominantly tubular growth pattern (n=52) and those whose tumors exhibited a predominantly papillary growth pattern (n=109). Tubular growth pattern was associated with combined vascular resection and the absence of macroscopic mucin. Several histological indexes were significantly higher for the tubular growth pattern than the papillary one, including tubular adenocarcinoma, depth of invasion, microscopic lymphatic invasion, venous invasion, perineural invasion, and necrosis. Although the survival curves overlapped (P=0.693), the rate of liver metastasis was significantly higher for the tubular growth pattern than for the papillary one (P=0.012). Genomic DNA analysis focusing on somatic mutations in codons 12 and 13 of KRAS and codon 600 of BRAF revealed only one (4%) KRAS and no BRAF mutation among the 25 tubular cases examined. In conclusion, the tubular growth pattern exhibited differences in some histologic indexes, in addition to a higher hepatic metastasis rate and a lower KRAS mutation frequency, compared with the papillary growth pattern, but no difference in prognosis was observed. The distinctiveness of this tubular neoplasm should be further examined in the future.

Intraductal papillary neoplasm of the bile duct, gastric type, arising in the intrapancreatic common bile duct could progress to colloid carcinoma: report of a case

Intraductal papillary neoplasm of the bile duct (IPNB) exists in a pathway of multistep-carcinogenesis toward cholangiocarcinoma. Four subtypes are observed in IPNB, pancreatobiliary type, intestinal type, gastric type, and oncocytic type, similarly to the corresponding disease in the pancreas, intraductal papillary mucinous neoplasm (IPMN). IPNB can present with or without macroscopically visible mucin secretion. IPNB usually progresses to tubular adenocarcinoma. However, there are a limited number of well-described cases of gastric-type IPNB progressing not to tubular adenocarcinoma but to colloid carcinoma. Herein, we present a case of an 82-year-old female patient with gastric-type IPNB in the intrapancreatic common bile duct without macroscopically visible mucin secretion, which progressed to colloid carcinoma. As IPNB, especially without visible mucin secretion, is considered to be a heterogeneous group of diseases, such an unexpected association could occur.

GNAS sequencing identifies IPMN-specific mutations in a subgroup of diminutive pancreatic cysts referred to as "incipient IPMNs"

Incipient intraductal papillary mucinous neoplasms (IPMNs) are poorly described subcentimeter pancreatic cysts with papillae and mucin similar to IPMNs. They are larger than pancreatic intraepithelial neoplasia but do not meet the cutoff size for IPMNs (≥ 1 cm). GNAS codon 201 mutations are hallmark genetic alterations of IPMNs. Hence, we sought to determine the GNAS status of incipient IPMNs to better classify these lesions. Incipient IPMNs from 3 institutions were histologically reassessed, manually microdissected, and the genomic DNA was extracted. Using a sensitive digital ligation technique, the mutational status of KRAS at codon 12 and GNAS at codon 201 was determined. We included 21 incipient IPMNs from 7 male and 12 female patients with a median age of 63 years (range, 40 to 76 y). Most patients underwent surgery for pancreatic ductal adenocarcinoma (N = 8) or ampullary adenocarcinoma (N = 3). The median incipient IPMN size was 4 mm (range, 2 to 7 mm), and a majority had gastric-foveolar (N = 11) or intestinal (N = 5) differentiation. The maximum dysplasia observed was intermediate, and most of the lesions had intermediate-grade dysplasia. Mutational analysis revealed KRAS codon 12 mutations in all 21 incipient IPMNs, whereas 7 lesions (33%) in 7 individual patients harbored GNAS codon 201 mutations. The presence of GNAS 201 mutations in incipient IPMNs suggests that a fraction of these cysts are in fact small IPMNs. Morphologically, incipient IPMNs do not appear to be high-risk lesions. Additional studies in a larger cohort are needed to define the relationship of incipient IPMNs to larger IPMNs and, more importantly, to determine their clinical significance.

Hepato-pancreato-biliary lesions are present in both Carney complex and McCune Albright syndrome: comments on P. Salpea and C. Stratakis

One of the key messages of recent Salpea and Stratakis work is to underline the clinical similarities shared by these syndromes that could be explained by a defect in the same signaling pathway, i.e. activation of the cAMP pathway. That being said, we would like to emphasize that hepatopancreato-biliary lesions are one additional feature shared both by Carney complex and McCune Albright syndrome.

Intracholecystic papillary-tubular neoplasm of the gallbladder presenting with jaundice

We herein report a case of intracholecystic papillary-tubular neoplasm (ICPN) of the gallbladder in which jaundice developed. A 58-year-old woman with jaundice was referred to our hospital. Computed tomography revealed a papillary tumor in the body of the gallbladder protruding into the bile duct. A transpapillary biopsy of the bile duct verified adenocarcinoma, and pancreatoduodenectomy with extended cholecystectomy was performed. The tumor spread macroscopically from the gallbladder body to the cystic duct, thus forming a polypoid mass protruding into the bile duct. This is a rare case of invasive carcinoma from ICPN leading to mechanical obstruction of the bile duct.

Intraductal papillary neoplasms of the bile duct: stepwise progression to carcinoma involves common molecular pathways

Intraductal papillary neoplasms of the bile duct are still poorly characterized regarding (1) their molecular alterations during the development to invasive carcinomas, (2) their subtype stratification and (3) their biological behavior. We performed a multicenter study that analyzed these issues in a large European cohort. Intraductal papillary neoplasms of the bile duct from 45 patients were graded and subtyped using mucin markers and CDX2. In addition, tumors were analyzed for common oncogenic pathways, and the findings were correlated with subtype and grade. Data were compared with those from 22 extra- and intrahepatic cholangiocarcinomas. Intraductal papillary neoplasms showed a development from preinvasive low- to high-grade intraepithelial neoplasia to invasive carcinoma. Molecular and immunohistochemical analysis revealed mutated KRAS, overexpression of TP53 and loss of p16 in low-grade intraepithelial neoplasia, whereas loss of SMAD4 was found in late phases of tumor development. Alterations of HER2, EGFR, β-catenin and GNAS were rare events. Among the subtypes, pancreato-biliary (36%) and intestinal (29%) were the most common, followed by gastric (18%) and oncocytic (13%) subtypes. Patients with intraductal papillary neoplasm of the bile duct showed a slightly better overall survival than patients with cholangiocarcinoma (hazard ratio (cholangiocarcinoma versus intraductal papillary neoplasm of the bile duct): 1.40; 95% confidence interval: 0.46-4.30; P=0.552). The development of biliary intraductal papillary neoplasms of the bile duct follows an adenoma-carcinoma sequence that correlates with the stepwise activation of common oncogenic pathways. Further large trials are needed to investigate and verify the finding of a better prognosis of intraductal papillary neoplasms compared with conventional cholangiocarcinoma.

Intraductal papillary neoplasms of the bile duct

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

GNAS and KRAS mutations are common in intraductal papillary neoplasms of the bile duct

Intraductal papillary neoplasms of the bile duct (IPNB) shows favorable prognosis and is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. Although activating point mutations of GNAS at codon 201 have been detected in approximately two thirds of IPMNs of the pancreas, there have been few studies on GNAS mutations in IPNBs. This study investigates the status of GNAS and KRAS mutations and their association with clinicopathological factors in IPNBs. We examined the status of GNAS mutation at codon 201 and KRAS mutation at codon 12&13, degree of mucin production and immunohistochemical expressions of MUC mucin core proteins in 29 patients (M/F = 15/14) with IPNB in intrahepatic and perihilar bile ducts (perihilar IPNB) and 6 patients (M/F = 5/1) with IPNB in distal bile ducts (distal IPNB). GNAS mutations and KRAS mutations were detected in 50% and 46.2% of IPNBs, respectively. There was no significant correlation between the status of GNAS mutation and clinicopathological factors in IPNBs, whereas, the status of KRAS mutation was significantly inversely correlated with the degree of MUC2 expression in IPNBs (p<0.05). All IPNBs with GNAS mutation only showed high-mucin production. Degree of mucin production was significantly higher in perihilar IPNBs than distal IPNBs (p<0.05). MUC2 and MUC5AC expression was significantly higher in IPNBs with high-mucin production than those with low-mucin production (p<0.01 and p<0.05, respectively). In conclusions, this study firstly disclosed frequent GNAS mutations in IPNBs, similarly to IPMNs. This may suggest a common histopathogenesis of IPNBs and IPMNs. The status of KRAS mutations was inversely correlated to MUC2 expression and this may suggest heterogeneous properties of IPNBs. IPNBs with high-mucin production are characterized by perihilar location and high expression of MUC2 and MUC5AC, irrespective of the status of GNAS and KRAS mutations.

Precancerous lesions of the biliary tree

The neoplasms of the biliary tree include the carcinomas of the intra- and extrahepatic bile ducts, the gallbladder and the ampulla. Two types of precancerous lesions precede these adenocarcinomas: the flat and non-tumour forming type that is called biliary intraepithelial neoplasia, and the papillary and tumour-forming type that has been named intraductal papillary neoplasm of the bile duct. Rarely also biliary mucinous cystic neoplasm can give rise to invasive biliary adenocarcinomas. This review discusses the pathological, molecular, epidemiological, clinical and prognostic features of the precancerous biliary lesions, separated according to their origin in the bile ducts, the ampulla and the gall bladder.

A comparison between intraductal papillary neoplasms of the biliary tract (BT-IPMNs) and intraductal papillary mucinous neoplasms of the pancreas (P-IPMNs) reveals distinct clinical manifestations and outcomes

BACKGROUND

Intraductal papillary mucinous neoplasm of the biliary tract (BT-IPMN) has been increasingly recognized as a biliary counterpart of intraductal papillary mucinous neoplasm of the pancreas (P-IPMN). However, there is limited information regarding whether BT-IPMNs and P-IPMNs behave in a similar fashion.

METHODS

We retrospectively compared clinicopathological variables between 9 patients with BT-IPMN and 44 patients with P-IPMN.

RESULTS

There was no significant difference in age between patients with BT-IPMN and those with P-IPMN. The male/female ratio was significantly higher in patients with P-IPMN than in those with BT-IPMN (P = 0.012). Clinical presentation with jaundice was more common in patients with BT-IPMN (67%) than in those with P-IPMN (4.5%, P = 0.002). In addition, serum levels of CEA and CA19-9 were higher in patients with BT-IPMN than in those with P-IPMN (P = 0.019 and P = 0.002, respectively). The pathological diagnosis of malignancy was significantly more common in patients with BT-IPMN (89%) than in those with P-IPMN (23%, P = 0.002). The association with invasive carcinoma was significantly more frequent in patients with BT-IPMN (44.4%) than in those with P-IPMN (6.8%, P = 0.008). Furthermore, survival time after surgical resection was significantly shorter in patients with BT-IPMN than in those with P-IPMN (P = 0.002).

CONCLUSION

These findings reveal differences in clinicopathological features and prognosis between BT-IPMN and P-IPMN, thereby suggesting distinct biological pathways underlying the pathogenesis of these neoplasms.