Bronchoscopic and transthoracic cytology and biopsy for pulmonary nonsmall cell carcinomas: performance characteristics by procedure and tumor type.

Recent advances have increased the demand for the accurate diagnosis of pulmonary nonsmall cell carcinoma (NSCLC) rendered by biopsy or cytology. However, precise classification is not possible in all cases. In this study, we investigated the performance characteristics of preresection bronchoscopic and transthoracic procedures for the diagnosis of NSCLC. The pathology files were searched for resected NSCLCs and carcinoid tumors with corresponding preresection cytology and/or biopsy cases. The preresection diagnoses were correlated with the resection diagnosis and the type of bronchoscopic or transthoracic procedure. Among the bronchoscopic procedures, endobronchial/transbronchial biopsy (ETBX) had the highest yield for obtaining a positive (malignant) diagnosis and was the best procedure for obtaining precise classification. For transthoracic procedures, fine-needle aspiration (FNA) and needle core biopsy (NCB) were similar in providing a positive (malignant) diagnosis; however, NCB was better than FNA in obtaining precise classification. From the perspective of the neoplasms, carcinoid tumors yielded a positive (malignant) specimen with accurate classification most often (e.g., 100% by ETBX). This was followed by squamous cell carcinoma and adenocarcinoma. In contrast, precise classification was not possible for adenosquamous carcinoma, large cell carcinoma, and large cell neuroendocrine carcinoma. Bronchoscopic and transthoracic procedures have different performance characteristics. Furthermore, the diagnostic yield is dependent on the histologic type of the neoplasm. While carcinoid tumors are accurately classified in most cases, some other neoplasms are difficult to diagnose and subclassify due to histologic complexity, poor differentiation, or sampling limitations.