Patients with known or suspected malignancies of the lung and with a medical indication for a bronchoscopy will be invited to participate in the study. All patients must be over 18 years old and must sign informed consent. The endoscopic examination of the bronchial tree will be performed using a commercially available flexible fluorescence bronchoscope (11004BI; Karl Storz; Culver City, CA) and the flexible white light video-bronchoscope (BF-T180; Olympus; Center Valley, PA).