Specimens interpreted as suspicious for carcinoma were considered negative for purposes of the study. Benign disease was more difficult to diagnose with TBNA cytology specimens, but aggregates of epithelioid cells and histiocytes consistent with granulomata were considered positive for sarcoidosis. The false positive and false negative rates of TBNA were not studied; however, no false positive results were suspected clinically.
Patient records were reviewed to determine the indication for bronchoscopy and results of radiographic studies, bron-choscopic findings, cytology and histology reports, surgical pathology reports and eventual outcome. The records of patients with positive TBNA were reviewed by two of the authors (JC, CM) with the intent of determining whether the positive TBNA result altered management and resulted in cost savings by avoiding further diagnostic studies. The authors determined which diagnostic tests would have been necessary in the event that the TBNA had proved negative, and the cost of these subsequent procedures was calculated and compared with the cost of adding TBNA to a routine bronchoscopy procedure.