At about 16:27 EST, the left wing of a Beech D50E caught fire while taxiing for takeoff at Myrtle Beach International Airport. The pilot was not injured. The pilot had landed to refuel and was taxiing for takeoff. As he performed a flight control check of the ailerons he saw the paint discoloring on the upper outboard wing skin. He taxied to an open area of the ramp, where he secured the airplane. After exiting the airplane, he noted fire at the outboard fuel tank vent, which was leaking fuel. He discharged a handheld fire extinguisher and nearly extinguished the fire. The airport fire rescue team then arrived and completed the job.