Carcinoma of the lung is the most common cause of cancer-related death in men and women. Prognosis correlates strongly with stage of disease at presentation and to some degree with the histological subtype of the tumor. Histological classifications of lung cancer were somewhat arbitrary and a matter of convenience. However, multiple lines of differentiation are often found within a single tumor, if it is sufficiently sampled. The new therapeutic approaches especially of non-small cell lung cancer place high demands on pathologists: a clear histological diagnosis with information on the predominant histological subtype is required, obtained by using additional immunohistochemical methods. Using molecular methods, predictive and prognostic factors for.
