[Problems in the histological classification of bronchial carcinomas].

Different histological classifications of pulmonary tumors, proposed and adopted over the last five decades, are briefly reviewed. Referring to the revised Histological Classification of Lung Tumors that was edited by an international committee of lung pathologists for WHO in 1977, different histologic types of bronchus carcinoma are presented in separate groups. Squamous carcinoma, small cell carcinoma, adenocarcinoma, and large cell carcinoma are differentiated in supra- and subgroups. Specific problems arising in the classification of mixed or combined tumors manifesting coexistence of different histologic growth types in the same tumor, are discussed in detail.