Use of IMP3, S100P, and pVHL immunopanel to aid in the interpretation of bile duct biopsies with atypical histology or suspicious for malignancy

Ancillary tests for hepatobiliary neoplasms: what we know and what we need to know

Ancillary tests are commonly used in the surgical pathology setting for diagnosing challenging neoplastic diseases of the liver and biliary tract, while histology and clinical correlation remain to be critically important. With continuous discoveries, more and more useful ancillary tests have become available, which can help distinguish between malignant and benign hepatocellular neoplasms, malignant and benign biliary tract entities, and intrahepatic and metastatic carcinomas. This review will focus on existing and emerging biomarkers (such as glutamine synthetase, organic anion transporting polypeptide 1B3, insulin-like growth factor-II mRNA binding protein-3, S100P, SMAD4, enhancer of zeste homolog 2, albumin, hepatocyte nuclear factor-1β, etc.) that can be used for the diagnosis, classification and prognostication of hepatobiliary neoplasms.

Cytopathology of Inflammatory Lesions of the Pancreatobiliary Tree

CONTEXT.—

A variety of inflammatory processes affect the pancreatobiliary tree. Some form mass lesions in the pancreas, mimicking pancreatic ductal adenocarcinoma, and others cause strictures in the bile ducts, mimicking cholangiocarcinoma. Acute pancreatitis, chronic pancreatitis, autoimmune pancreatitis, and paraduodenal groove pancreatitis have distinct cytopathologic features that, when correlated with clinical and imaging features, may lead to correct classification preoperatively. In biliary strictures sampled by endobiliary brushing, the uniform features are the variable presence of inflammation and reactive ductal atypia. A potential pitfall in the interpretation of pancreatobiliary fine-needle aspiration and duct brushing specimens is ductal atypia induced by the reactive process. Recognizing cytologic criteria that differentiate reactive from malignant epithelium, using ancillary testing, and correlating these features with clinical and imaging findings can lead to the correct preoperative diagnosis.

OBJECTIVE.—

To summarize the cytomorphologic features of inflammatory processes in the pancreas, describe the cytomorphology of atypia in pancreatobiliary specimens, and review ancillary studies applicable for the differential diagnosis of benign from malignant ductal processes for the purpose of best pathology practice.

DATA SOURCES.—

A PubMed review was performed.

CONCLUSIONS.—

Accurate preoperative diagnosis of benign and malignant processes in the pancreatobiliary tract can be achieved with application of diagnostic cytomorphologic criteria and correlation of ancillary studies with clinical and imaging findings.

S100P as a marker for poor survival and advanced stage in gallbladder carcinoma

AIMS

Gallbladder carcinomas usually present in advanced stages and has a dismal prognosis despite modern imaging techniques and aggressive surgical intervention. Identification of biologic markers for early diagnosis and improved therapeutic strategies is thus of paramount importance. S100P has been identified in a variety of malignant neoplasms of the gastrointestinal and pancreaticobiliary systems, but it is not yet known if S100P expression is associated with clinically-relevant characteristics of gall bladder carcinoma. The aims of the present study were: 1) to investigate the relationship between S100P expression and histological type, grade, tumor-node-metastasis stage, presence of vascular invasion, perineural invasion and necrosis; and 2) to evaluate for any S100P-defined difference in the risk for tumor recurrence or death.

METHOD

Immunostains for S100P were performed on 4 tissue microarray blocks containing 91 cases of gall bladder carcinoma.

RESULT

The intensity of S100P staining was significantly associated with pathological T stage 4 (p = 0. 0238). Staining intensity ≥3 in ≥25% tumor cells was associated with pathological T stage 4 (p = 0.0005). A higher S100P immunoreactivity score (IRS) was significantly associated with higher TNM stage (p = 0.0341). Age (p = 0.0485), presence of vascular invasion (p = 0.0359), pathological T stage (p = 0.0291) and TNM stage (p = 0.0153) were significantly associated with tumor recurrence. Intense S100P reactivity was associated with decreased overall survival [hazard ratio = 9.614; 95% confidence interval (CI), 1.873-49.338; p = 0.0067].

CONCLUSION

Our findings indicate that S100P over-expression is a potential prognostic marker for gall bladder carcinoma and is significantly associated with advanced tumor stage and poorer survival.

Approaches to Biopsy and Resection Specimens from the Ampulla

The ampulla of Vater gives rise to a versatile group of cancers of mixed/hybrid histologic phenotype. Ampullary carcinomas (ACs) are most frequently intestinal or pancreatobiliary adenocarcinomas but other subtypes, such as medullary, mucinous, or signet ring/poorly cohesive cell carcinoma, may be encountered. Ampullary cancer can also be subclassified based on immunohistochemical features, however these classification systems fail to show robust prognostic reliability. More recently, the molecular landscape of AC has been uncovered, and has been shown to have prognostic and predictive significance. In this article, the site-specific, histologic, and genetic characteristics of ampullary carcinoma and its precursor lesions are discussed.

Design of an immunohistochemistry biomarker panel for diagnosis of pancreatic adenocarcinoma

BACKGROUND

Challenges still exist in differentiating pancreatic adenocarcinoma from benign disease. The use of adjuvant testing of tissue biopsies has demonstrated potential diagnostic value. We designed a proof of concept study to first validate four individual immunohistochemistry biomarkers and then combine them into a panel to boost overall diagnostic sensitivity.

METHODS

Malignant and benign pancreas from 27 pancreaticoduodenectomy specimens underwent immunohistochemistry staining with VHL, IMP3, S100A4, S100P. Using ROC curve analysis, threshold criteria for number of cells staining were chosen for each biomarker. Biomarkers were then evaluated as a panel for their ability to discriminate malignant from benign specimens.

RESULTS

Diagnostic sensitivity of VHL, IMP3, S100A4, and S100P were 75.0%, 79.2%, 45.8%, and 0%. When VHL, IMP3, and S100A4 were grouped into a panel, they were able to distinguish cancer from normal tissue with a sensitivity of 100% and a specificity of 96%.

CONCLUSIONS

The high diagnostic value of an IHC panel consisting of VHL, IMP3, and S100A4 on surgical specimens suggests the need for future prospective studies of these biomarkers on biopsy specimens.

Primary Liver Cancers-Part 1: Histopathology, Differential Diagnoses, and Risk Stratification

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the 2 most common primary malignant liver tumors, with hepatocellular and bile ductular differentiation, respectively. This article reviews the key histopathological findings of these 2 primary liver cancers and includes a review of the role of ancillary testing for differential diagnosis, risk stratification according to the American Joint Committee on Cancer (AJCC) staging recommendation, and a review of precancerous lesions. A literature review was conducted to identify articles with information relevant to precancerous precursors, current histopathological classification, ancillary testing, and risk stratification of primary malignant liver tumors. The histomorphology of normal liver, preinvasive precursors, primary malignancies, and morphological variants, and the utilization of ancillary tests for the pathological diagnosis are described. Dysplastic nodules are the preinvasive precursors of HCC, and intraductal papillary neoplasms of bile ducts and biliary intraepithelial neoplasia are the preinvasive precursors of CC. Benign liver nodules including focal nodular hyperplasia and adenomas are included in this review, since some forms of adenomas progress to HCC and often they have to be differentiated from well-differentiated HCC. A number of morphological variants of HCC have been described in the literature, and it is necessary to be aware of them in order to render the correct diagnosis. Risk stratification is still dependent on the AJCC staging system. The diagnosis of primary liver carcinomas is usually straightforward. Application of the appropriate ancillary studies aids in the differential diagnosis of difficult cases. The understanding of the carcinogenesis of these malignancies has improved with the standardization of the pathological classification of preinvasive precursors and studies of the molecular pathogenesis. Risk stratification still depends on pathological staging.

Cholangiocarcinoma

This article focuses on cholangiocarcinoma, both intrahepatic and extrahepatic. The various classification schemes based on anatomic location, macroscopic growth pattern, microscopic features, and cell of origin are outlined. The clinicopathologic, immunohistochemical and molecular differences between intrahepatic cholangiocarcinoma and extrahepatic cholangiocarcinoma, as well as differences in the 2 subtypes of intrahepatic cholangiocarcinoma, are discussed. Finally, precursor lesions, prognosis, treatment, and promising new potential targeted therapies are reviewed.

Practical Immunohistochemistry in Neoplastic Pathology of the Gastrointestinal Tract, Liver, Biliary Tract, and Pancreas

CONTEXT

- Immunomarkers with diagnostic, therapeutic, or prognostic values have been increasingly used to maximize the benefits of clinical management of patients with neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas.

OBJECTIVES

- To review the characteristics of immunomarkers that are commonly used in surgical pathology practice for neoplasms of the gastrointestinal tract, liver, biliary tract, and pancreas, and to summarize the clinical usefulness of immunomarkers that have been discovered in recent years in these fields.

DATA SOURCES

- Data sources include literature review, authors' research data, and personal practice experience.

CONCLUSIONS

- Immunohistochemistry is an indispensable tool for the accurate diagnosis of neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas. Useful immunomarkers are available to help distinguish malignant neoplasms from benign conditions, determine organ origins, and subclassify neoplasms that are morphologically and biologically heterogeneous. Specific immunomarkers are also available to help guide patient treatment and assess disease aggressiveness, which are keys to the success of personalized medicine. Pathologists will continue to play a critical role in the discovery, validation, and application of new biomarkers, which will ultimately improve patient care.

The Evolving Role of Pathology in New Developments, Classification, Terminology, and Diagnosis of Pancreatobiliary Neoplasms

Pancreatobiliary tract lesions are increasingly being discovered because of more sensitive imaging modalities. Magnetic resonance imaging has identified incidental pancreatic cysts in 13.5% of patients of progressively increasing age. Pancreatobiliary tissue is more accessible through endoscopic ultrasound and magnetic resonance imaging-guided biopsy procedures, and is now an integral part of pathologists' routine practice. Accordingly, several new tumor categories have been recently recognized, including intraductal tubulopapillary neoplasm, a new addition to tumoral intraepithelial neoplasms. Other entities have been reclassified, including the recent transition to 2-tiered grading of preinvasive neoplasms, as well as new perspectives on the distinctive biologic behavior of oncocytic intraductal papillary mucinous neoplasms (IPMNs) compared with other IPMN subtypes. This has led to proposals for revised staging of virtually every segment of the pancreatobiliary tree, with theranostic markers becoming an integral part of workup. Ki-67 is now an integral part of the classification of neuroendocrine tumors, with new definitions of "high-grade neuroendocrine carcinoma." Although bile duct brushings have opened new avenues for diagnosis, their sensitivity remains low and often requires concomitant fluorescent in situ hybridization to better define ambiguous cases. Various molecular pathways have been elucidated for pancreatic cysts, including KRAS for ductal neoplasia, GNAS for intestinal IPMNs, RNF3 for mucinous cysts, and VHL for serous cystic neoplasms, all key players in diagnostic workup. Integration of these updates into our understanding of pancreatobiliary disease requires active engagement of pathologists for appropriate specimen triage, judicious interpretation of results, and incorporation into reporting and staging. They also provide exciting opportunities for targeted therapy.

Reg proteins promote acinar-to-ductal metaplasia and act as novel diagnostic and prognostic markers in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignant tumor. Acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia (PanIN) are both precursor lesions that lead to the development of PDAC. Reg family proteins (Reg1A, 1B, 3A/G, 4) are a group of calcium-dependent lectins that promote islet growth in response to inflammation and/or injuries. The aim of this study was to establish a role for Reg proteins in the development of PDAC and their clinical value as biomarkers. We found that Reg1A and Reg3A/G were highly expressed in the ADM tissues by immunohistochemistry. In the 3-dimensional culture of mouse acinar cells, Reg3A promoted ADM formation with concurrent activation of mitogen-acitvated protein kinase. Upregulation of Reg1A and Reg1B levels was observed as benign ductal epithelium progresses from PanIN to invasive PDAC. Patients with PDAC showed significantly higher serum levels of Reg1A and Reg1B than matching healthy subjects. These results were further validated by the quantification of Reg 1A and 1B mRNA levels in the microdissected tissues (22- and 6-fold increases vs. non-tumor tissues). Interestingly, patients with higher levels of Reg1A and 1B exhibited improved survival rate than those with lower levels. Furthermore, tissue expressions of Reg1A, Reg1B, and Reg4 could differentiate metastatic PDAC in the liver from intrahepatic cholangiocarcinoma with 92% sensitivity and 95% specificity. Overall, our results demonstrate the upregulation of Reg proteins during PDAC development. If validated in larger scale, Reg1A and Reg1B could become clinical markers for detecting early stages of PDAC, monitoring therapeutic response, and/or predicting patient's prognosis.

The role of S100P and IMP3 in the cytologic diagnosis of pancreatic adenocarcinoma

PURPOSE

The aim of this study was to assess the role of the two markers, S100P and IMP3, in differentiating between pancreatic ductal adenocarcinoma (PDA) and non-neoplastic pancreatic tissue in (fine needle aspiration cytology) FNAC.

PATIENTS AND METHODS

This is a retrospective study that included 72 cases presented with pancreatic mass, where endoscopic guided FNAC was taken from pancreatic lesions. The final histopathologic diagnosis was considered the gold standard. Cell blocks were stained with anti S100P, and IMP3. Nuclear immunoreactivity with or without cytoplasmic staining for the first marker, and cytoplasmic staining for the second marker was considered specific. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and total accuracy of the two markers, as well as the combined accuracy of both markers were calculated.

RESULTS

S100P achieved 96.4% sensitivity, 93.3% specificity, 98.2% PPV, 87.5% NPV and 95.8% total accuracy, while IMP3 achieved 91.2% sensitivity, 86.7% specificity, 96.2% PPV, 72.2% NPV and 90.3% total accuracy for PDA. Both markers showed a total combined accuracy of 89%. S100P showed strong and diffuse staining pattern in most of cases, while the staining pattern for IMP3 was moderate and focal in most of cases.

CONCLUSION

Both markers were sensitive and specific for diagnosis of PDA. The staining pattern for S100P was easier to evaluate than IMP3.

Diagnostic value of maspin in distinguishing adenocarcinoma from benign biliary epithelium on endoscopic bile duct biopsy

Histopathologic distinction between benign and malignant epithelia on endoscopic bile duct biopsy can be extremely challenging due to small sample size, crush artifact, and a propensity for marked inflammatory and reactive changes after stent placement. Our previous studies have shown that the insulin-like growth factor II mRNA-binding protein 3, S100P, and the von Hippel-Lindau gene product (pVHL) can help the distinction. This study analyzed 134 endoscopic bile duct biopsy specimens (adenocarcinoma 45, atypical 31, and benign 58) by immunohistochemistry for the expression of maspin, a serine protease inhibitor. The results demonstrated that (1) maspin expression was more frequently detected in malignant than in benign biopsies; (2) malignant biopsies frequently showed diffuse, strong/intermediate, and combined nuclear/cytoplasmic staining patterns for maspin, which were much less commonly seen in benign biopsies; (3) the malignant staining patterns for maspin observed in atypical biopsies were consistent with follow-up data showing that 67% of these patients were subsequently diagnosed with adenocarcinoma; (4) a maspin+/S100P+/pVHL- staining profile was seen in 75% of malignant biopsies but in none of the benign cases. These observations demonstrate that maspin is a useful addition to the diagnostic immunohistochemical panel (S100P, pVHL, and insulin-like growth factor II mRNA-binding protein 3) to help distinguish malignant from benign epithelia on challenging bile duct biopsies.

Utility of immunohistochemistry in the pancreatobiliary tract

CONTEXT

Immunohistochemistry has become a useful ancillary study in the identification and classification of pancreatic neoplasms. The diagnostic accuracy has been significantly improved because of the continuous discoveries of tumor-associated biomarkers and the development of effective immunohistochemical panels.

OBJECTIVES

To identify and classify pancreatic neoplasms by immunohistochemistry.

DATA SOURCES

Literature review and authors' research data and personal practice experience were used.

CONCLUSIONS

To better guide therapeutic decisions and predict the prognostic outcome, it is crucial to make an accurate diagnosis of a pancreatic neoplasm. Application of appropriate immunohistochemical panels enables pathologists to differentiate pancreaticobiliary adenocarcinomas from reactive conditions and to identify rare types of pancreatic neoplasms. Knowing the utilities and pitfalls of each tumor-associated biomarker is essential to avoiding a potential diagnostic error because an absolutely cancer-specific biomarker does not exist. This article reviews frequently used tumor-associated biomarkers, provides lists of effective immunohistochemical panels, and recommends a diagnostic algorithm as a standard approach to pancreatic neoplasms.

Sensitivity of alternative testing for pancreaticobiliary cancer: a 10-y review of the literature

BACKGROUND

Biliary strictures present a diagnostic challenge to differentiate benign disease from hepatopancreaticobiliary (HPB) malignancies. Endoscopic retrograde cholangiopancreatography cytology is commonly performed in these patients; however, its sensitivity for diagnosis of HPB malignancy is poor (41.6%). Many adjunctive tests have been investigated to improve the sensitivity of HPB biopsies. To determine the best tests available, however, we reviewed the literature and performed a comparative analysis of all recently investigated tests and their sensitivities.

METHODS

A PubMed search identified articles published between 2003 and 2014, describing alternate methods for diagnosing HPB malignancies, reported sensitivity, final pathology, and had data available online. Meta-analysis was conducted for tests with multiple articles. Tests with the highest sensitivity and specificities were reported.

RESULTS

A total of 77 studies were identified. Meta-analysis was performed on the sensitivity of EUS-FNA (74.2%), fluorescence in situ hybridization (54.2%), immunostain of insulin-like growth factor 2 mRNA-binding Protein 3 (IMP3; 80.4%), IMP3 + cytology (86.4%), K homology domain containing protein overexpressed in cancer (KOC; 85.9%), S100P (77.8%), serum CA19-9 (69.3%), and K-ras mutations (47.0%) to detect malignancy. Ultimately, 12 tests were identified with superior sensitivity (85.3%-100%) and specificities (81.6%-100%) including stricture scrapping, brush sectioning, IMP3 stain + cytology, IMP3+S100A4, bile carcinoembryonic cell adhesion molecule 6 protein (±CA19-9), bile micro RNA (miRNA)-135b, serum miRNA-RNU2-1f, serum miRNA-21 (+CA19-9), peripheral blood mononuclear cells miRNA-27a-3p (+CA19-9), serum miRNA-16 + miRNA-196a (+CA19-9), peripheral blood mononuclear cells mRNAs h-TERT + CK20 + CEA + C-MET.

CONCLUSIONS

We recommend immunostaining with a panel of IMP3+KOC + S100A4 + cytology to achieve maximum sensitivity and specificity from HPB biopsies. One biliary protein (carcinoembryonic cell adhesion molecule 6) and several RNAs (bile and blood) offer exceptional sensitivity and specificity and should be tested prospectively in larger populations. Overall, this review identifies several tests to improve the sensitivity of diagnostic algorithms to identify HPB malignancies.

Immunohistochemical distinction between intrahepatic cholangiocarcinoma and pancreatic ductal adenocarcinoma

Distinction between primary intrahepatic cholangiocarcinoma (ICC) and metastatic pancreatic ductal adenocarcinoma (PDA) on a liver biopsy is essentially impossible histologically but has important clinical implications. In this study, 41 ICCs and 60 PDAs were immunohistochemically evaluated for the expression of S100P, pVHL, IMP3, maspin, MUC5AC, and CK17 proteins. The results showed pVHL expression in 29 (71%) ICCs but in only 3 (5%) PDAs. S100P, MUC5AC, and CK17 were frequently expressed in PDAs, seen in 57 (95%), 40 (67%), and 36 (60%) cases, respectively. In contrast, only 11 (27%), 5 (12%), and 5 (12%) ICC cases expressed these proteins. IMP3 was expressed in 37 (90%) ICC and 54 (90%) PDA cases with equal frequency. All 60 (100%) PDA and 30 (73%) ICC cases showed positive maspin immunoreactivity. A S100P-/pVHL+/MUC5AC-/CK17- staining pattern was essentially indicative of ICC, whereas the S100P+/pVHL-/MUC5AC+/CK17+ and S100P+/pVHL-/MUC5AC-/CK17+ staining patterns were suggestive of PDA. These observations demonstrate that S100P, pVHL, MUC5AC, and CK17 are a useful immunohistochemical panel that may help distinguish primary ICC from metastatic PDA.

Pathological diagnosis of flat epithelial lesions of the biliary tract with emphasis on biliary intraepithelial neoplasia

Flat epithelial lesions of the biliary tract cannot be detected by the image analysis, and the diagnosis entirely depends on pathological examination. The biliary tract is often affected by inflammatory conditions, and the resultant changes of the biliary epithelium make it difficult to differentiate them from neoplasia. Thus, the pathological diagnosis of biliary flat epithelial lesions can be challenging. In the biliary tract, there are several forms of intraepithelial neoplasia of the flat type, and biliary intraepithelial neoplasia (BilIN) is known as one of such lesions that represent the multistep cholangiocarcinogenesis. In this article, the diagnostic criteria and the differential diagnosis of biliary flat epithelial lesions, particularly focusing on BilIN, were presented and discussed to provide help to advance clinical and research applications of the BilIN system.

Clinicopathological significance of S100 protein expression in cholangiocarcinoma

BACKGROUND AND AIM

Cholangiocarcinoma arising in the large bile ducts undergoes a multistep carcinogenesis process in chronic biliary diseases, and biliary intraepithelial neoplasia is known as a precursor lesion. This study examined the expression of S100 proteins in the multistep cholangiocarcinogenesis to clarify their clinicopathological significance.

METHODS

Immunohistochemical analysis was performed for the expression of S100A2, S100A4, S100A6, and S100P. Bile concentrations of S100P were measured using enzyme-linked immunosorbent assay.

RESULTS

The immunohistochemical expression of the S100 proteins was increased in biliary intraepithelial neoplasia as well as invasive adenocarcinoma of perihilar cholangiocarcinoma. Among the proteins, S100P expression was most drastically increased during the multistep carcinogenesis process. In cases with perihilar and extrahepatic cholangiocarcinoma, the immunohistochemical expression of S100A2 in cholangiocarcinoma cells significantly correlated with the histological grade, lymph node metastasis, clinical stage, and a poor survival rate of the patients. The bile levels of S100P were increased significantly in patients with cholangiocarcinoma compared with those in patients with lithiasis. Receiver operating characteristic curve analysis showed that S100P bile concentration was an indicator of cholangiocarcinoma with a sensitivity of 93% and a specificity of 70%.

CONCLUSIONS

These results suggest that S100P may be useful for the detection of cholangiocarcinoma as tissue and bile biomarkers, and the immunohistochemical expression of S100A2 is a potential prognostic marker in cholangiocarcinoma patients.