Visceral and Parietal Pleural Invasion
Description
Visceral and Parietal Pleural Invasion is defined as invasion beyond the elastic layer or to the surface of the visceral pleura. Invasion of one or more layers of the pleura covering the lung (visceral pleura), such as invasion beyond the elastic layer of the pleura. The elastic layer may be identified on hematoxylin and eosin (H&E) stains or by special stains looking for the elastic fibers. An elastic stain is not needed in most cases to assess the pleura for invasion, only in those cases where the distinction between PL0 and PL1 is unclear on H&E sections. Elastic stains may also be helpful in cases where the visceral and parietal pleura are adherent, making it difficult to identify the boundary between the visceral pleural surface and the parietal pleura. VPI is relevant for peripheral lung tumors. The presence of visceral pleural invasion by tumors smaller than 3 cm changes the T category from pT1 to pT2 and increases the stage from IA to IB in patients with no nodal disease or stage IIA to IIB in patients with peribronchial or hilar nodes. Studies have shown that tumors smaller than 3 cm that penetrate beyond the elastic layer of the visceral pleura behave similarly to similar-size tumors that extend to the visceral pleural surface. Visceral pleural invasion should therefore be considered present not only in tumors that extend to the visceral pleural surface, but also in tumors that penetrate beyond the elastic layer of the visceral pleura. Four to six layers of visceral pleura may be described by the pathologist.Notes
**Note 1:** **Physician Statement** * Physician statement of Visceral and Parietal Pleural Invasion can be used to code this data item when no other information is available. **Note 2:** **Criteria for coding** * A surgical resection **must** be done to determine if the visceral and/or parietal pleural is involved. * *Exception*: In situ tumors (/2) can be coded 0 based on biopsy or surgical resection * Do not use imaging findings to code this data item| Code | Description |
|---|---|
| 0 | No evidence of visceral pleural invasion identified Tumor does not completely traverse the elastic layer of the pleura Stated as PL0 Primary tumor is in situ Non-invasive neoplasm (behavior /2) No evidence of primary tumor |
| 4 | Invasion of visceral pleura present, NOS Stated as PL1 or PL2 |
| 5 | Tumor invades into or through the parietal pleura OR chest wall Stated as PL3 |
| 6 | Tumor extends to pleura, NOS; not stated if visceral or parietal |
| 8 | Not applicable: Information not collected for this case (If this item is required by your standard setter, use of code 8 will result in an edit error.) |
| 9 | Not documented in medical record No surgical resection of primary site is performed Visceral Pleural Invasion not assessed or unknown if assessed or cannot be determined |