Malignant neoplasm of liver, primary, unspecified as to type

This code signifies a primary cancerous tumor originating within the liver tissue, where the specific histological type of the malignancy has not been determined or documented. It indicates that the liver itself is the site where the cancer first developed, rather than a spread from another organ.

Apply this code when documentation clearly states a primary malignant neoplasm of the liver, but the pathology report or physician notes do not specify the exact type (e.g., hepatocellular carcinoma, cholangiocarcinoma). This is appropriate for initial diagnoses where further workup is pending or when the specific type remains unknown after investigation.

• Do not use if the liver malignancy is secondary (metastatic); instead, code the primary site and a secondary liver malignancy code.
• If the specific type of primary liver cancer is known (e.g., hepatocellular carcinoma), use the more specific code (e.g., C22.0).
• Always sequence this code as the principal diagnosis when it is the primary reason for the encounter, unless another condition meets the principal diagnosis definition.