Endobronchial ultrasound-guided transbronchial needle aspiration which is known as the EBUS procedure is a low risk procedure performed using bronchoscopy to sample chest lesions. A needle is passed through the bronchoscope to biopsy the chest lesion. Every lesion is usually biopsied 3 to 7 times. In most cases the investigators apply a syringe with negative pressure to the needle inserted into lesion for biopsy. In some cases the investigators don't apply any negative pressure. There are no studies to evaluate which one is better, applying syringe suction or no suction.