Homogenization of sputum with dithiothreitol for early diagnosis of pulmonary malignancies.

Homogenization of sputum with dithiothreitol (DTT) has not been used in cytology for the detection of malignant cells. We examined the efficacy of this method as compared to the conventional "pick and smear" (PS) method. Smears were prepared from sputum samples using the PS technique to act as the control. The remaining sputum was digested with an equal volume of 0.3% DTT in 70% ethanol at room temperature. The cells were washed with 35% ethanol and smears prepared. The DTT-treated specimens gave a much higher concentration of evenly distributed cells. The background was clear and the morphology comparable to that of the control. More positive cases were detected with the DTT than the conventional PS technique. Homogenization of sputum with DTT is a simple and effective method of screening for pulmonary malignancies.