"PL0: represents tumour invading either the subpleural lung parenchyma or superficially the pleural connective tissue beneath the elastic layer"
"PL1: refers to a tumour that invades beyond the elastic layer without being exposed on the pleural surface"
"PL2: refers to a tumour that is exposed on the pleural surface, but it does not involve adjacent anatomic structures"
Expected headings
"Grading"
"There are three described levels of invasion (based on histology):"