Secondary malignant neoplasm of unsp respiratory organ

This code signifies the presence of a metastatic cancerous tumor that originated elsewhere in the body and has spread to an unknown or unspecified respiratory organ. It indicates that the primary site of the malignancy is not located within the respiratory system itself.

Use this code when documentation confirms a secondary malignant neoplasm affecting a respiratory organ, but the specific respiratory organ (e.g., bronchus, lung, pleura) is not identified. This is appropriate when the medical record clearly states "metastatic cancer to an unspecified respiratory organ" or similar ambiguous phrasing.

• Always strive for greater specificity if available in the documentation; codes like C78.00, C78.01, or C78.02 are more precise.
• This code should be sequenced after the code for the primary malignancy, if known.
• Avoid using this code if the documentation specifies a primary respiratory neoplasm, as that would be a different code series (e.g., C34.- for lung).