An apparatus for thermal treatment of a tissue mass having an elongated housing having a proximal and a distal end and defining a longitudinal axis, and further including at least two electrodes supported at its distal end and mounted for rotation to facilitate entry and passage through a tissue mass. A drive shaft may be disposed within the elongated housing and operatively engageable with the electrodes for causing their rotational movement. The apparatus may include an electrode gear and a drive shaft gear in cooperative engagement whereby rotation of the drive shaft causes corresponding rotation of the electrodes. Preferably, a motor is operatively connected to the drive shaft causing its rotational movement. Desirably, the distal end of the electrodes are threaded. A method for thermally treating a tissue mass is disclosed.