Visceral pleural invasion: Pathologic criteria and use of elastic stains: Proposal for the 7th edition of the TNM classification for lung cancer
Carcinoma, Non-Small-Cell Lung
Staining and Labeling
Based on the currently available data, we propose that the next tumor, node, metastasis (TNM) revision by International Union Against Cancer and American Joint Committee on Cancer define VPI as invasion beyond the elastic layer (PL1) including invasion to the visceral pleural surface (PL2). The abbreviation PL for pleura is recommended rather than P to avoid confusion with the existing use of p (pathologic) TNM in distinction from c (clinical) TNM. We also recommend that elastic stains be used in cases when the distinction between PL0 and PL1 is not clear based on evaluation of hematoxylin and eosin sections.