An apparatus for treating tissue in a tissue treatment region. The apparatus can comprise an electrode ring having an interior perimeter and an electrode probe having a proximal end and a distal end. The distal end of the electrode probe can be structured to axially translate relative to the interior perimeter of the electrode ring. The electrode ring and the electrode probe can be operably structured to conduct current therebetween when at least one of the electrode ring and the electrode probe is energized by an energy source. Further, the energy source can be a Radio Frequency (RF) energy source, a pulsed energy source, an irreversible electroporation energy source, or a pulsed irreversible electroporation energy source. A current from the energy source can be selected to non-thermally ablate tissue in the tissue treatment region.