An ablation device includes a cannula having a distal end and a lumen, an array of electrodes deployable from within the lumen, each of the electrodes having a first configuration when inside the lumen, and a second configuration when unconfined outside the lumen, the electrodes having respective distal ends that point at least partially towards a distal direction when deployed, and an operative electrode secured to the distal end of the cannula. In one embodiment, the operative electrode has a shape that is different from the array of electrodes. In another embodiment, the operative electrode is not retractable within the lumen.
