Diagnostic Sensitivity of Sputum and Bronchial Washing Cytology in Bronchogenic Carcinomas Confirmed by Bronchoscopic Biopsy

Kim, Joon Mee; Min, Soo Kee; Chu, Young Chae; Cho, Chul Ho

Abstract

To evaluate the role of sputum and bronchial washing for the diagnosis of lung carcinoma, we studied the sensitivity of both cytologic techniques using the biopsy confirmed cases from 228 patients. Among them, 123 cases were squamous cell carcinomas, 42 cases were adenocarcinomas, 48 cases were small cell carcinomas, one case was large cell carcinoma, and 14 cases were other types of carcinoma including poorly differentiated carcinomas. Three hundreds and ninety two sputa and 173 sputa were obtained in the pre- and post- bronchoscopic periods. Bronchial washing had been taken once in each patient. The overall sensitivity of the sputum cytology was 0.52 and that of the bronchial washing 0.63, while it increased to 0.83 when a combination of both techniques. Squamous cell carcinomas were diagnosed to the great extent in which sensitivities were 0.59 and 0.74, in sputum and bronchial washing, respectively. The post-bronchoscopic sputa showed higher sensitivity (0.44) than pre-bronchoscopic sputa (0.30). The sensitivity of sputa increased from 0.34 to 0.49 when three samples were examined compared to the single examination. The accuracy of cell typing was 94.0% in sputa and 93.8% in bronchial washing. Repeated sputum examination including post- bronchoscopic sputa is warranted to improve sensitivity and a complementary role of both cytologic techniques can be postulated by these data.