[The DNA content in precancer, peripheral cancer and carcinoids of the lung (histospectrophotometric research)].

Histospectrophotometric study of DNA content shows that, at the lung periphery, oval structures with atypia, adenomatosis with atypia, dysplasia and basal cell hyperplasia with bronchial epithelium atypia should be regarded as precancerous lesions. Carcinoma in situ and bronchoalveolar carcinoma are distinguished from the foci of epithelial dysplasia by an increase of DNA content and appearance of hetero- and aneuploidy. Aneuploidy is observed in 97% peripheral lung carcinoma and is combined with a heterogeneity of cells by their DNA content. Poorly differentiated squamous cell carcinoma, adenocarcinoma and large cell carcinoma are characterized by a marked heterogeneity which correlates with a degree of tumour morphological atypia. Bronchoalveolar carcinoma is a heterogeneous group of tumours with a different histogenesis and pronounced anaplasia which is expressed in a various degree of polyaneuploidy and heteroploidy. Small cell lung carcinoma, a special group of tumours, which, as distinct from other carcinoma types, is characterized by a low, sometimes diploid DNA content which does not correlate with its malignancy.