Secondary malignant neoplasm of other respiratory organs

This diagnosis code signifies the presence of a metastatic cancerous tumor in a respiratory organ other than the lung, bronchus, or pleura. This means the primary cancer originated elsewhere in the body and has spread to a respiratory structure like the trachea, larynx, or diaphragm.

Assign this code when medical record documentation clearly indicates a secondary malignancy affecting a respiratory organ not specifically covered by other C78.3x codes. This typically applies when a patient with a known primary cancer presents with new or worsening symptoms related to metastatic disease in the trachea, larynx, or mediastinum.

• Always sequence the primary malignancy code before this secondary site code.
• Ensure the documentation specifies a respiratory organ other than lung, bronchus, or pleura; otherwise, a more specific C78.3x code may be appropriate.
• Do not use this code for primary tumors originating in these respiratory organs; those would be coded to the C30-C39 range.