J91.0
BillableMalignant pleural effusion
HCC Category Mapping
V28HCC 17 — Metastatic Cancer and Acute Leukemia
0.368What This Code Means
This is a buildup of fluid around the lungs caused by cancer that has spread to the lining of the lungs. The fluid accumulation can make it difficult to breathe and requires medical treatment.
Coding Tips
- •Always verify the underlying malignancy and code it separately, as J91.0 specifically indicates the pleural effusion is related to cancer
- •Ensure documentation clearly states the effusion is malignant (cancer-related) rather than benign to distinguish from other pleural effusion codes like J91.8
Clinical Significance
Malignant pleural effusion indicates fluid accumulation in the pleural space caused by cancer, most commonly lung cancer, breast cancer, or lymphoma. This is a marker of advanced/metastatic disease and carries a poor prognosis with median survival of 3-12 months. Accurate coding is critical because it captures the severity of the underlying malignancy and the palliative care resource burden including repeated thoracentesis and possible pleurodesis.
Documentation Requirements
- ✓Documentation that the pleural effusion is malignant (positive cytology, known pleural metastases, or clinical determination by the treating oncologist)
- ✓Identification and coding of the underlying primary malignancy as a separate diagnosis
- ✓Pleural fluid cytology results if available
- ✓Imaging confirming pleural effusion with features suggesting malignancy (nodular pleural thickening, associated mass)
- ✓Treatment plan including drainage, pleurodesis, or indwelling pleural catheter placement
Commonly Confused Codes
J91.8 — Pleural effusion in other conditions classified elsewhere is used for non-malignant effusions secondary to other diseasesJ90 — Pleural effusion not elsewhere classified is for effusions without identified causeJ86.9 — Pyothorax without fistula is infected pleural fluid, which may co-occur with malignant effusionC78.2 — Secondary malignant neoplasm of pleura codes the metastatic disease directly and may be coded alongside J91.0
Code Hierarchy
└J91Pleural effusion in conditions classified elsewhere└J91.0Malignant pleural effusion
└J91.0Malignant pleural effusion