punch biopsy
(... BY-op-see)
A procedure in
          which a small round piece of tissue about the size of a
          pencil eraser is removed using a sharp, hollow, circular
          instrument. The tissue is then checked under a microscope
          for signs of disease. A punch biopsy may be used to check
          for certain types of cancer, including skin, vulvar, and
          cervical cancer. It may also be used to check for certain
          skin conditions and changes that may lead to
          cancer.
