A biopsy device is provided for obtaining a tissue sample, such as a breast tissue biopsy sample. The biopsy device includes a disposable probe assembly with an outer cannula having a distal piercing tip, a cutter lumen, and a cutter tube that rotates and translates past a side aperture in the outer cannula to sever a tissue sample. The biopsy device also includes a reusable handpiece with an integral motor and power source to make a convenient, untethered control for use with ultrasonic imaging. The reusable handpiece incorporates a probe oscillation mode to assist when inserting the distal piercing tip into tissue. An integral vacuum motor assists prolapsing tissue for effective severing as well as facilitating withdrawal of the tissue samples and bodily fluids from the biopsy site into a detachable, self-contained canister for transporting the separated biopsy samples and fluid for pathology assessment, avoiding biohazards in a clinical setting.
