I have a leak that seems to be coming from the shower pan drain, all tile and grout seems intact. The leak at first looked likeit was coming frm the bottom of the trap, but I saw that it was water building around the joint from the vertical pipe (PVC) from the trap to the drain above. Any suggestions? I would love to avoid ripping our the shower pan (which is plastic, walls ceramic tile)

Sometimes if the shower base isn't bedded properly it will give a bit around the drain lip when someone steps in and puts weight on the shower floor.
In time this will rupture the seal under the drain lip and allow water to leak past and down the trap raiser. The correct way would be to open up the ceiling and loosen the drains retaining nut and run a rope of plumbers putty or silicon jel under the lip and tighten the nut.
But before you go through the hassle try this. Dry off around the drain lip and jam silicon jel under the drain lip. Let it set up and cure. To test remove the strainer and jam wet rags in drain to stop it off and fill the base with a inch of water and let it set. Look for moisture on the ceiling. If you have none you've repaired your leak. If there's moisture follow the first set of instructions. Good luck, Tom