Endoscopic diagnosis of perihilar cholangiocarcinoma

<p>Diagnosis of biliary stricture lesions involves distinguishing between benign and malignant conditions and assessing the extent of progression in operable cases. Using dynamic CT for lesions detected through blood tests or abdominal ultrasound, the macroscopic features, progression extent, and degree of vascular infiltration are evaluated. In cases with a high likelihood of cancer, consideration is given to the feasibility of surgical intervention and, if possible, the anticipated surgical approach. Subsequently, endoscopic retrograde cholangiopancreatography (ERCP), along with intraductal ultrasound (IDUS), peroral cholangioscopy (POCS), and/or biliary biopsies and bile cytology, is employed for differentiating between benign and malignant diagnoses and assessing the longitudinal progression of the biliary duct. For challenging cases, such as flat-type strictures, a focus is placed on obtaining biopsies from the narrowed segment, while for nodular or papillary types prone to superficial progression, mapping biopsies are performed at appropriate locations considering the planned surgical approach. Endoscopic diagnostic techniques, including ERCP, carry the risk of adverse events. Therefore, understanding the advantages and disadvantages of various diagnostic methods, such as cytology, biopsy, peroral cholangioscopy, and ultrasound-guided fine-needle aspiration, is crucial for efficiently and reliably reaching a diagnosis.</p>