Cytologic diagnosis of lung tumors from bronchial brushings of Chinese patients in Hong Kong.

In 1,156 single or multiple specimens obtained from fiberoptic bronchoscopy on 1,016 Chinese patients in Hong Kong, a positive diagnosis of malignancy was made on cytologic examination in 288 and a histologic type assigned. On histologic examination of tissue, malignant tumors were diagnosed in 284 cases. The total positive yield by cytology was 88%, and the overall cytologic accuracy in correlation with histology was 73%. Comparing cases typed by cytology and by histology, the diagnostic accuracy of cytology was 83% in squamous-cell carcinoma, 81% in small-cell carcinoma, 69% in adenocarcinoma and 46% in large-cell carcinoma. The detection rate of nonbronchogenic tumors was 50%. Bronchogenic tumors showed a low male:female ratio, 1.96:1, whereas 80% of squamous-cell carcinomas and 45% of adenocarcinomas occurred in males. All seven cases of bronchogenic carcinoma in patients under 40 years of age occurred in males.