Flexible bronchoscopy in nonvisualized carcinoma of the lung.

Of 1,000 consecutive patients undergoing fiberoptic bronchoscopy, 331 eventually were proven to have primary lung cancer. Of the 331 carcinomas, 253 were beyond the visual range of the flexible bronchoscope. However, under fluoroscopic guidance, the diagnosis of carcinoma was established in 194 (76.7%) of these nonvisualized tumors. Cytologic analysis of brush specimens was more often positive for malignancy than specimens obtained by forceps biopsy. An expert cytologist and experienced bronchoscopy team are esential for a high percentage of reliable positive diagnoses in bronchogenic carcinoma.