[Cytological studies in pneumonological diagnosis].

The following principles for the use of cytological examinations in pneumology are suggested: 1. The aim of cytological sputum examinations is diagnosis of tumors and not early detection of bronchial cancer in risk groups. 2. The diagnostic accuracy of cytological examinations depends mainly on the preparatory techniques. 3. Cytology and histology are complementary methods in the diagnosis of tumors and should always be combined. 4. Immunocytochemistry and electronmicroscopy are rarely indicated and are at best complementary to conventional microscopic diagnosis. 5. Cytological examinations for Pneumocystis carinii and other opportunistic germs in immuno-deficient patients should be confined to clinical centers with adequate experience.