A new method of preparing specimens for cytodiagnosis of lung cancer.

A simple and effective method for concentrating sputum in the preparation of smears for cytodiagnosis of lung cancer was developed. The procedure, which utilizes a fixative consisting of 2,3-dihydroxy-1,4-dithiol-butane, 3,5-ditert-butyl-4-hydroxy-toluene, polyoxyethylene-cetyl-ether, polyethylene glycol 1540, and ethyl alcohol in distilled water permitted preparation of an amucoid, thin smear. Sputum was collected in a screw-cap plastic tube containing the fixative. After 12 hours mucus in the sputum was liquefied and the cellular elements were obtained from the bottom of the tube. Cellular morphology was well preserved for cytodiagnosis. Microscopic observation was facilitated by lysis of the mucus. Estimation of cellular origin was rather easy because of the distinct fixation. Cells from the sputum sediment following liquefaction were more representative of the entire specimen than with a random selection method. The new method should be useful not only in hospitals but also in mass surveys.