[Precancer and cancer of the lung].

The problem of the patho- and morphogenesis of the lung cancer is discussed. Central and peripheral lung cancer differ from each other not only by their localization but by the etiology, pathogenesis, morphogenesis, histogenesis and precancer epithelial changes as well. The central cancer morphogenesis is connected with the precancer changes of the large bronchi epithelium resulting as a rule from the carcinogen inhalation. The morphogenesis of the peripheral cancer is less studied and belongs to the problem of the "carcinoma in the scar". Peripheral lung carcinoma is shown to develop in the pneumosclerotic foci after tuberculosis, pneumonia, lung infarct, around foreign bodies. The histogenesis of the lung cancer is connected with the pluripotential and unipotential cell precursors of the lung epithelia the variety of which is particularly pronounced at the lung periphery, this explaining the differences in the histological types of central and peripheral lung cancer and complexity of its morphological classification.