A biopsy apparatus includes a driver assembly and biopsy probe mechanism drivably coupled to the driver assembly. The biopsy probe mechanism includes a biopsy cannula having a cylindrical side wall that defines a lumen and has a side port located near a distal end that extends through the side wall to the lumen. A thumbwheel mechanism includes a thumbwheel mounted to the driver assembly to rotate about a first rotational axis, the first rotational axis being substantially perpendicular to the longitudinal axis. A first gear is mounted to the thumbwheel for coaxial rotation with the thumbwheel about the first rotational axis. A second gear is mounted to the biopsy cannula for coaxial rotation with the biopsy cannula about the longitudinal axis, the second gear being located to be drivably engaged by the first gear. The housing is grasped and the thumbwheel rotated with a single hand.
