Bronchial brushing during fiberoptic bronchoscopy for the cytodiagnosis of lung cancer: comparison with sputum and bronchial washings.

In a study of 50 cases of bronchogenic carcinoma in which brushings and washings during fiberoptic bronchoscopy, as well as sputum cytopathologic examinations were performed in the same patients, accuracy rates were respectively: 76 per cent, 76 per cent and 56 per cent. The main cytologic differences setting brush apart from wash and sputum specimens referred to the arrangement of tumor cells as well as the distribution of chromatin within their nuclei. These differences appeared related to cell degeneration which was minimal in brush materials and maximum in sputum specimens. Only six cases were assigned a different cell type of bronchogenic carcinoma when brush cytopathologic diagnoses were compared with results obtained by biopsy or lobectomy specimens. Our findings are consistent with the view that the brush technique is very accurate for the cytodiagnosis of lung cancer and becomes also rather specific once cytologic characteristics of the fresher samples obtained become familiar to the cytopathologist. Non-observance of the special characteristics of these better preserved cellular samples is the major pitfall as to diagnosing, cell typing and judging degree of differentiation of bronchogenic carcinoma in brush cytology specimens.