Transbronchial needle aspiration for histology specimens.

Fine-gauge (22-G) transbronchial needle aspiration (TBNA) has significantly added to the diagnostic yield of FOB, and in some institutions has become routine in staging bronchogenic carcinoma. Cytologic examination of the specimen obtained by n228G TBNA, however, has several limitations. The mediastinal aspirate can be contaminated by tumor cells from respiratory secretions, giving false positive diagnoses of unresectability. The diagnosis of benign conditions can seldom be made. Using 18-G TBNA, we can obtain specimens for histologic examination from paratracheal, peribronchial, and carinal areas by FOB. Both 18-G and 22-G TBNA were performed in 34 patients with radiographic abnormalities involving mediastinal or hilar areas. Tissue for histologic examination was obtained in 17 patients (50 percent) using 18-G TBNA and was diagnostic in 11 (32 percent), including three patients with benign conditions. The overall diagnostic yeild of 18-G TBNA was 41 percent (14/34 patients), increasing the yield of FOB from 50 percent to 58 percent. There were no false positive results and few minor complications. 18-G TBNA is effective in obtaining tissue for histologic examination and diagnosing benign conditions. In selected cases this technique increases the diagnostic yield of FOB.