This is probably the most commonly performed type of biopsy.
It is done with the help of a fiber-optic endoscope (light, flexible tube) which the doctor inserts into the gastrointestinal tract (alimentary tract endoscopy), urinary bladder (cystoscopy), abdominal cavity (laparoscopy), joint cavity (arthroscopy), mid-portion of the chest (mediastinoscopy), or trachea and bronchial system (laryngoscopy and bronchoscopy), either through a natural body orifice or a small surgical incision.
The doctor can directly visualize an abnormal area on the lining of the organ which is diseased and cut it into tiny bits of tissue with forceps attached to a long cable that runs inside the endoscope.