C78.39

HCC Category Mapping

What This Code Means

Cancer that has spread to other specific parts of the respiratory system (such as pleura, mediastinum, or thymus) from a cancer that started elsewhere.

Coding Tips

• •Review documentation carefully to identify which specific respiratory organ is involved; this code is for organs not covered by C78.30-C78.32
• •Ensure the primary malignancy is coded separately to establish the metastatic relationship

Clinical Significance

Secondary malignant neoplasm of other respiratory organs captures metastatic disease to respiratory structures not specifically classified elsewhere, such as the trachea, bronchi, or nasopharynx. This code is used when the metastatic site is a known respiratory organ but falls outside the more commonly coded lung, pleura, and mediastinum categories.

Documentation Requirements

• ✓Primary cancer site must be documented and coded separately
• ✓Specific identification of the respiratory organ involved (trachea, bronchus, etc.)
• ✓Imaging or pathological confirmation of metastatic disease
• ✓Clinical symptoms related to the metastatic respiratory involvement
• ✓Treatment plan for the respiratory metastasis

Commonly Confused Codes