Test performance and predictors of accuracy of endoscopic ultrasound-guided fine-needle aspiration for diagnosing biliary strictures or masses

Contributions of endoscopic ultrasonography-guided tissue acquisition (EUS-TA) to the diagnostics of biliary stricture and gallbladder lesions

Endoscopic ultrasonography (EUS) provides high spatial resolution and more detailed images than other diagnostic modalities. Furthermore, EUS-guided tissue acquisition (EUS-TA), such as EUS-guided fine needle aspiration or biopsy (EUS-FNA/FNB), is an indispensable tool in pancreaticobiliary disease diagnostics, supporting a conclusive pathological diagnosis. In this review, we evaluate the current status and the usefulness of EUS-TA for the diagnostics of the following biliary tract diseases: (A) biliary stricture diagnostics, (B) biliary tract cancer (BTC) itself, and (C) staging of advanced BTC. Previous reports have shown that EUS-FNA for biliary lesions is a safe procedure that is useful in differentiating biliary cancer from benign lesions and in the staging of BTC. On the other hand, the diagnostic performance of EUS-TA for bile duct lesions is reported to be similar to that of transpapillary biopsy. Overall, EUS-TA for biliary lesions may be a safe and effective method, but it should be performed with an understanding of the risk of serious adverse events such as bile leakage and peritoneal dissemination of cancer. It is recommended for distal biliary stricture lesions for which endoscopic retrograde cholangiopancreatography cannot confirm the diagnosis or gallbladder lesions if they do not require the needle to pass through the biliary lumen.

Primary Sclerosing Cholangitis-Associated Cholangiocarcinoma: From Pathogenesis to Diagnostic and Surveillance Strategies

Cholangiocarcinoma (CCA) is the most common malignancy in patients with primary sclerosing cholangitis (PSC), accounting for 2-8% of cases and being the leading cause of death in these patients. The majority of PSC-associated CCAs (PSC-CCA) develop within the first few years after PSC diagnosis. Older age and male sex, as well as concomitant inflammatory bowel disease (IBD) or high-grade biliary stenosis, are some of the most relevant risk factors. A complex combination of molecular mechanisms involving inflammatory pathways, direct cytopathic damage, and epigenetic and genetic alterations are involved in cholangiocytes carcinogenesis. The insidious clinical presentation makes early detection difficult, and the integration of biochemical, radiological, and histological features does not always lead to a definitive diagnosis of PSC-CCA. Surveillance is mandatory, but current guideline strategies failed to improve early detection and consequently a higher patient survival rate. MicroRNAs (miRNAs), gene methylation, proteomic and metabolomic profile, and extracellular vesicle components are some of the novel biomarkers recently applied in PSC-CCA detection with promising results. The integration of these new molecular approaches in PSC diagnosis and monitoring could contribute to new diagnostic and surveillance strategies.

Endoscopic Ultrasound in the Diagnosis of Extrahepatic Cholangiocarcinoma: What Do We Know in 2023?

Extrahepatic cholangiocarcinoma (CCA) is a rare and aggressive type of cancer, presenting as a mass or as a biliary stricture. This review summarizes the utility of endoscopic ultrasound (EUS) in the detection, staging, and determination of the differential diagnosis, especially when no cause of bile duct dilatation is revealed by cross-sectional imaging. The EUS detection rate for distal CCAs is higher than that for the proximal CCAs. The accuracy of T staging varies between 60 and 80%, and vascular involvement is correctly assessed by conventional EUS. EUS-tissue acquisition from the primary tumors is reserved for unresectable or metastatic CCA, especially in distal strictures or mass CCAs. For proximal lesions, EUS could be performed as an adjunctive to ERCP sampling when the latter is inconclusive. EUS is not appropriate for assessing the malignant features of lymph nodes in CCAs. Lymph node EUS-tissue acquisition should be performed only if it changes the surgical decision. Perhaps the development of EUS-fine needle biopsy and the detection of molecular genetic alteration will increase the diagnostic yield in CCAs.

Multidisciplinary Approach to Indeterminate Biliary Strictures

Biliary strictures that remain unclassified after cross-sectional imaging and endoscopic retrograde cholangiopancreatography-based tissue sampling are defined as indeterminate biliary strictures (IDBS). A substantial proportion of biliary strictures fall into this category due to low sensitivity of brush cytology and intraductal biopsy. Over last few decades, several modalities have emerged for the evaluation of IDBS. Of these, cholangioscopy and endosonography are the frontrunners and have cemented their place for the evaluation of IDBS. Both of these modalities are widely available, and therefore, biliary strictures that remain uncharacterized after their utilization represent IDBS in the current era.

Endoscopic Ultrasound for the Diagnosis and Staging of Biliary Malignancy

Cholangiocarcinoma (CCA) is the most common neoplasm of the biliary tract. The biological behavior and prognosis of CCA vary depending on the tumor's location in the biliary tree, dictating a different diagnostic, and treatment approach. Establishing a diagnosis of CCA remains a challenge and up to 20% of biliary strictures can yield indeterminate results, despite extensive evaluation. Endoscopic ultrasound (EUS) has become an effective diagnostic tool, as it provides high-quality images of the bile duct and allows for the sampling of strictures in the same plane of view. In this chapter, we explore the utility of EUS as a diagnostic and staging tool for biliary cancers.

Primary sclerosing cholangitis-associated cholangiocarcinoma: special considerations and best practices

Introduction: Primary sclerosing cholangitis (PSC) is a rare, heterogenous, chronic cholestatic liver disease that causes fibro-inflammatory destruction of the intra- and/or extrahepatic bile ducts. The disease course may be variable, though in many cases it ultimately leads to biliary cirrhosis and its associated complications. PSC is also associated with malignancies, in particular cholangiocarcinoma (CCA), a dreaded neoplasm of the biliary tract with a poor prognosis. Risk stratification and surveillance for this malignancy are important components of the care of patients with PSC.Areas covered: In this review, we discuss important considerations in the clinical epidemiology, risk factors, diagnosis, and surveillance of PSC-associated CCA.Expert opinion: Despite growing awareness of PSC, high-quality evidence regarding the management of PSC and its associated risk of CCA remains limited. Early diagnosis of PSC-associated CCA remains difficult, and treatment options are limited, especially when diagnosed at later stages. The recent introduction of recommendations for CCA surveillance will likely improve outcomes, though an optimal surveillance approach has yet to be validated prospectively. Further research is needed in the development of high-accuracy (and noninvasive) surveillance and diagnostic tools that may facilitate earlier diagnosis of CCA and potential disease cure.

Extrahepatic cholangiocarcinoma: Current status of endoscopic approach and additional therapies

The prognosis of patients with advanced or unresectable extrahepatic cholangiocarcinoma is poor. More than 50% of patients with jaundice are inoperable at the time of first diagnosis. Endoscopic treatment in patients with obstructive jaundice ensures bile duct drainage in preoperative or palliative settings. Relief of symptoms (pain, pruritus, jaundice) and improvement in quality of life are the aims of palliative therapy. Stent implantation by endoscopic retrograde cholangiopancreatography is generally preferred for long-term palliation. There is a vast variety of plastic and metal stents, covered or uncovered. The stent choice depends on the expected length of survival, quality of life, costs and physician expertise. This review will provide the framework for the endoscopic minimally invasive therapy in extrahepatic cholangiocarcinoma. Moreover, additional therapies, such as brachytherapy, photodynamic therapy, radiofrequency ablation, chemotherapy, molecular-targeted therapy and/or immunotherapy by the endoscopic approach, are the nonsurgical methods associated with survival improvement rate and/or local symptom palliation.