Diagnostic sensitivity of different techniques in the diagnosis of lung tumors with the flexible fiberoptic bronchoscope. Comparison of brush biopsy, imprint cytology of forceps biopsy, and histology of forceps biopsy.

Brush and forceps biopsies were done consecutively in 186 cases of pulmonary neoplasia with a flexible fiberoptic bronchoscope guided by x-ray television fluoroscopy. Imprint and histologic sections were prepared from all forceps biopsy specimens. The three techniques were compared for their diagnostic sensitivity. As a result 84.9% of all imprints, 80.6% of brush biopsy specimens, and 62.9% of histologic sections were positive for malignancy. The sensitivity of brush biopsy specimens was independent of the location and morphology of the tumors, but the sensitivity of forceps biopsy specimens was lower in neoplasms unidentified by bronchoscopy. The sensitivity of the diagnostic accuracy when all three methods were used jointly was 97.3%, and the specificity was 100%. Agreement in the final morphologic tumor type was found in 130 of 150 cases (86.7%) by positive brush biopsy specimens, in 136 of 158 cases (86.1%) by positive imprint cytology, and in 104 of 117 cases (88.9%) by positive histology from forceps biopsy specimens. For routine bronchoscopy, all three methods should be used in combination to obtain the highest diagnostic yield.