An ablation system includes an ablation electrode assembly operatively connectable to sources of electrosurgical energy and cooling fluid. The electrode assembly includes a hub defining a chamber therein at least one electrically conductive ablation needle extending from the hub, the ablation needle including a distal end portion configured to penetrate tissue, said distal end portion being electrically and thermally conductive for establishing electric and thermal communication with the tissue a heat sink operatively connected to the ablation needle, the heat sink being connected to the ablation needle to draw energy away from at least the distal end portion thereof, the heat sink including a proximal end extending into the chamber of the hub and a conduit fluidly connected to the hub for delivering fluid into the chamber thereof from the source of fluid, wherein the fluid withdraws energy from the proximal end of the heat sink.
