The Diagnostic Dilemma of Malignant Biliary Strictures

Abstract

The differential diagnosis for biliary strictures is broad. However, the likelihood of malignancy is high. Determining the etiology of a biliary stricture requires a comprehensive physical exam, laboratory evaluation, imaging, and ultimately tissue acquisition. Even then, definitive diagnosis is elusive, and many strictures remain indeterminant in origin. This literary review examines the diagnostic dilemma of biliary strictures and presents innovations in both histochemical and endoscopic techniques that have increased the diagnostic power of differentiating benign and malignant strictures. The field of tissue biopsy is revolutionizing with the advent of free DNA mutation profiling, fluorescence in situ hybridization (FISH), and methionyl t-RNA synthetase 1 (MARS 1), which allow for greater testing sensitivity. Endoscopic ultrasound, endoscopic retrograde cholangiopancreatography (ERCP), cholangioscopy, confocal laser endomicroscopy, and intraductal ultrasound build upon existing endoscopic technology to better characterize strictures that would otherwise be indeterminate in etiology. This review uses recent literature to insert innovative technology into the traditional framework of diagnostic methods for malignant biliary strictures.

MRCP Combined With CT Promotes the Differentiation of Benign and Malignant Distal Bile Duct Strictures

“…Most of previous studies were based on CT, MRCP or MRCP combined with CE-MRI and focused on the extrahepatic bile duct or the full range of the bile duct, the risk factors for malignant BSs were not consistent ( 6 – 8 , 11 , 18 , 20 ). Although MRI/MRCP is superior to CT in differentiating between malignant and benign BSs ( 1 , 2 , 16 ), the specificity of MRCP combined with CE-MRI still needs to be improved ( 15 , 23 ), with a specificity of 70%–85% ( 15 ). Furthermore, CT is the preferred initial modality in differentiating between malignant and benign DBSs ( 24 ).…”

“…Endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasonography (EUS) are the most widely used endoscopic diagnostic modalities in suspected DBSs ( 4 ); however, these techniques are invasive and operator dependent ( 11 – 13 ) and may lead to complications such as seeding metastasis ( 4 ) or pancreatitis ( 14 ). In addition, the combination of biliary brushing and intraductal biopsy has a sensitivity of only 60%–70% ( 15 ). Noninvasive imaging techniques, including ultrasound (US), computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP), are the common initial examination methods used for suspected DBSs prior to the use of these more invasive techniques.…”

Biliary Strictures and Cholangiocarcinoma – Untangling a Diagnostic Conundrum

“…Real time microscopic diagnosis using CLE allows interrogation of the epithelium with high resolution, using intra-ductal fluorescein dye injection. Due to reduced positive predictive value and specificity when used in combination with ERCP, CLE is reserved for strictures still indeterminate following assessment using POC and IDUS – despite a sensitivity of 98% compared to ERCP alone (45%) ( 63 ).…”

Title: Endoscopic retrograde cholangiopancreatography and carbohydrate antigen 19-9 in the differential diagnosis of biliary strictures

“…The development achieved in recent years in diagnostic techniques such as multiphasic computed tomography, magnetic resonance imaging, and endoscopic ultrasound has contributed to the differentiation between benign and neoplastic strictures. ERCP is commonly used as a minimally invasive technique to drain the bile duct using a prothesis and to obtain a pathological sample by brushing the bile duct (1,(6)(7)(8)(9).…”