Cell lineage-specific immunohistochemical markers in biliary intraepithelial neoplasia: Implications for subclassification and grading.

Biliary intraepithelial neoplasia (BilIN), a precursor to cholangiocarcinoma, is categorized into low- and high-grade based on histological characteristics. Although gastric, intestinal, and biliary phenotypes of BilIN have been identified, detailed analyses of their immunophenotypic profiles using cell lineage-specific markers remain limited. This study aimed to define the immunohistochemical profiles of BilIN lesions, subclassify them based on their immunophenotypes, and correlate these profiles with histological grades.