Most American dermatologists perform biopsies with scalpels or with punches. The diameter of the American punch is wider at its base than at the cutting edge. The tapered circumference gives the punch a conical shape. Penetration of the skin with the punch is produced by a rotary movement of the heavy handle of the punch. European dermatologists prefer motor-driven punches. The cylindrical punch-knife, also called trepan, was originally described by E. Kromayer in 1905.1 The shaft of the punch-knife is attached to a handpiece which is connected through a flexible cable to a mounted high-speed dental motor. Since 1927, I have used a motor whose speed was controlled with the aid of a rheostat knob located on the base, and since 1953, a foot-controlled rheostat has been used.
The following technique is employed: After disinfecting and anesthetizing the selected site, the punch fixed to the handpiece is
WOLF M. USE OF ROTARY PUNCHES FOR SKIN BIOPSY. AMA Arch Derm. 1955;71(5):640–641. doi:10.1001/archderm.1955.01540290080023