Flow cytometric evaluation of bronchoscopic washings and lavage fluid for DNA aneuploidy as an adjunct in the diagnosis of lung cancer and tumors metastatic to the lung.

The presence of DNA aneuploidy (deviation from an exact multiple of the diploid amount of DNA) has been used to aid in the diagnoses of several malignancies. We undertook this study to determine if the addition of flow cytometric analysis (FCA) of bronchial washings and lavage specimens for the presence of DNA aneuploidy would increase the yield from bronchoscopy in the diagnosis of lung cancer and other tumors metastatic to the lung. Fifty-nine patients with a variety of both benign (33) and malignant (26) pulmonary disorders had specimens divided and submitted for both FCA and routine cytologic examination. The presence of an "obviously visible" second, aneuploid peak on the DNA histograms proved to be highly specific for the presence of malignancy, but lacked sensitivity. It was concluded that FCA is a promising technique for increasing the diagnostic yield from bronchoscopy at no increased risk to the patient. However, further studies are needed prior to its routine clinical application.