Comparative Analysis for Diagnostic Yield of Small Cell Lung Cancer by Cytology and Histology During the Same Bronchoscopic Procedure

Abstract

BackgroundBiopsy, brushing, and transbronchial needle aspiration (TBNA) are the most common methods used for the diagnosis of small cell lung cancer during the same diagnostic bronchoscopic procedure. However, it is not clear which method provides better results. Patients and MethodsA retrospective analysis was performed of 140 patients who had undergone video bronchoscopy for diagnostic purposes. Bronchial brushings were obtained from all subjects. Biopsy specimens were also obtained from all subjects, except for 6 cases that could not be sampled; the TBNA method was used for some special lesions. The results were analyzed separately by histology and cytology. ResultsThe diagnostic yield of cytology was significantly greater than that of histology (P < .01) and that of conventional smear preparations in cytology was obviously greater than that of hematoxylin and eosin stains in histology (P < .01). The false-negative results were significantly lower with cytology than with histology (P < .01). Also, the cases of sampling site restriction with cytology were distinctly less than those with histology (P < .05). Stretch deformation of the tissue structure and cell morphology was the main reason for the false-negative results in the histologic diagnosis. The use of TBNA resolved all 4 cases of hilar adenopathy and 2 cases of lesions outside the bronchus. Multiple brushings of the tissue adjacent to cancer tissue and liquid-based preparations of cancerous necrotic tissue can significantly reduce the false-negative results from biopsy. ConclusionsThe diagnostic yield of cytologic examination of brushings and TBNA for small cell lung cancer was superior to that of histologic examination of hematoxylin and eosin stains and immunohistochemistry.