During this test a thin fibreoptic tube is inserted into your breathing tubes, through the nose or the mouth, to view the tubes and take a biopsy (remove cells or tissue) to see if there are cancer cells present. It is usually undertaken under local anaesthetic. You may be given medicine to make you sleepy and relaxed.  A specialist doctor does this procedure in an operating theatre environment. EBUS is a similar procedure where an ultrasound probe is used to access tissue or enlarged lymph glands through the airways in order to take a sample to see if this is abnormal or cancer cells are present.