Early detection of precancerous lesions in dysplasias of the lung by rapid DNA image cytometry.

Hematoxylin-and-eosin-stained cytologic smears of sputum from 28 patients with dysplastic and suspicious cell findings were subjected to DNA image cytometry after Feulgen restaining. The nuclear DNA contents were measured with a TV-based image-analysis system, the Leitz TAS plus, combined with an automatic microscope. Computation of DNA data was performed according to an algorithm for the diagnosis and grading of malignancy. Of the 19 cases that were proven to be malignant in the follow-up, either by histologic examination, sputum cytology, fine needle aspiration biopsy or autopsy, the algorithm identified 17 as malignant in a stage (dysplasia) in which cytology was not yet able to present a definite diagnosis of malignancy. Only two cases of bronchial carcinoma were not detected in the state of dysplasia by this procedure. The periods between the DNA diagnosis of malignancy in dysplasia and the morphologic evidence of cancer varied from three days up to six months. Of the 11 cases that had been classified as benign by the algorithm, 9 were confirmed as benign during the clinical follow-up. Rapid DNA image cytometry appears able to separate squamous dysplasias of the lung into precancerous and nonprecancerous lesions.