Neoplasm of uncertain behavior of liver and biliary passages

This code signifies the presence of a liver or biliary passage lesion where the pathologist cannot definitively classify it as benign or malignant based on current microscopic examination. It indicates an indeterminate neoplastic process requiring further investigation or follow-up.

Apply this code when pathology reports describe a tumor or mass in the liver, gallbladder, bile ducts, or ampulla of Vater as "uncertain behavior," "borderline," "atypical proliferation," or "neoplasm of undetermined malignant potential." Documentation must explicitly state the uncertainty of the lesion's nature.

• Do not use this code if the pathology definitively states benign or malignant; use the appropriate benign or malignant neoplasm code.
• Always review the final pathology report. If subsequent biopsies or resections provide a definitive diagnosis, update the code accordingly.
• This code often requires additional codes for symptoms or signs prompting the investigation.