How much brushing is enough for the diagnosis of lung tumors?

Background: Bronchoscopic investigations of lung tumors require high diagnostic accuracy. Sometimes the combination of brush biopsy with cytologic and histologic examination of forceps-obtained biopsy specimens fails to diagnose tumors. Techniques with a minimum risk and low cost when repeated several times could increase the efficiency of tumor diagnosis and help to avoid rebronchoscopy.
Methods: Repeated brush biopsies were done during one bronchoscopic examination in 270 patients with pulmonary neoplasias using a flexible fiberoptic bronchoscope guided by radiographic video fluoroscopy. The results of up to five brush biopsies were compared for their diagnostic sensitivity.
Results: Singly, 68-77% of the specimens showed malignant findings. With repeated brushing, the sensitivity of the diagnostic accuracy increased to 89.6%. In the periphery of the bronchial tree, the sensitivity of brush biopsy was slightly lower in bronchoscopically invisible tumors. In 222 of 242 (91.7%) patients with positive results of brush biopsy, there was agreement in the final typing of tumor morphology.
Conclusion: For routine bronchoscopy, repeated brush biopsy should be done to obtain the highest diagnostic yield.