The cytologic examination of sputum and bronchial secretions has proved to be an extremely valuable adjunct in the diagnosis of carcinoma of the lung. The practical value of the method was first demonstrated by Dudgeon and Wrigley1 in 1935. Their method consisted essentially in making films of fresh sputum, fixing, while wet, in Schaudinn's solution and staining with hematoxylin and eosin. Subsequent studies by Barrett,2 Gowar3 and especially the thorough investigation of the subject by Wandall4 served to reemphasize the importance of a painstaking cytologic examination of sputum as an important link in the examination of patients believed to be suffering from primary bronchogenic carcinoma.
A study of bronchoscopically removed secretions was advocated by Herbut and Clerf,5 who felt that bronchial secretions are superior to sputum as a source of carcinoma cells. The method of fixation and the staining technic used were those advocated by