Detection of pulmonary neoplasms by bronchial washings. Are cell blocks a diagnostic aid?

While cell blocks of bronchial washings are often routinely prepared, their usefulness as adjuncts to the diagnosis of pulmonary neoplasms has not been evaluated. Bronchial washings obtained from 111 patients in whom clinical or radiographic evidence raised the suspicion of a pulmonary neoplasm were reviewed. The smears and cell block preparations were studied independently of each other without knowledge of the original diagnoses. Discrepancies between the smear and cell block diagnoses were noted in 17 cases. Smears detected more neoplasms (52) than cell blocks (43). However, four cell blocks were positive, while the corresponding smears were negative. According to these results, the use of cell blocks increased the diagnostic yield from 52 to 56 cases, for an increase of 9%. Cell blocks will increase the diagnostic yield of bronchial washings, albeit for a small number of patients. However, a positive result will have an obvious influence on patient management and will obviate incremental costs and risks attendant to more invasive diagnostic procedures.