Epithelial tumors of the lung

Our knowledge and understanding of bronchopulmonary tract tumors have grown considerably; modern pathology enables the phenotyping of many tumors with increasingly improving techniques and tools and, arguably, improving criteria. By the same token, at least some of the new data may not be readily grafted onto traditional classification schemes. Some traditional designations will be dropped and replaced. And, although it has been overenthusiastically argued that molecular classifications may be attained, that ideal might not be truly an improvement. For classifications to be useful, they should be relatively simple, easily reproducible, and clinically significant. Still, modern marker pathology has revealed new vistas for the evaluation, diagnosis, and therapy of at least some tumors. These developments merit optimism but also caution from clinicians and pathologists.