Carcinoma in situ of liver and biliary system

This code signifies the presence of abnormal, non-invasive epithelial cells confined to the ducts or glands of the liver or biliary system, without evidence of invasion into surrounding tissue. It represents a pre-malignant condition, often referred to as intraepithelial neoplasia, within these specific anatomical sites.

Apply this code when pathology reports confirm carcinoma in situ affecting the liver parenchyma, intrahepatic bile ducts, gallbladder, or extrahepatic bile ducts. Documentation must clearly state "carcinoma in situ" or "intraepithelial neoplasia" and specify the liver or biliary system as the primary site.

• Differentiate carefully from malignant neoplasms (e.g., hepatocellular carcinoma, cholangiocarcinoma) which involve invasion.
• Ensure the pathology report explicitly states "in situ"; do not assume based on "dysplasia" alone.
• This code should be sequenced as the primary diagnosis when the carcinoma in situ is the reason for the encounter.