The removal of a small piece of lung tissue to be checked by a pathologist for cancer or other diseases. The tissue may be removed using a bronchoscope (a thin, lighted, tube-like instrument that is inserted through the trachea and into the lung). It may also be removed using a fine needle inserted through the chest wall, by surgery guided by a video camera inserted through the chest wall, or by an open biopsy. In an open biopsy, a doctor makes an incision between the ribs, removes a sample of lung tissue, and closes the wound with stitches.