There are many causes for spots on top of an LCD rear projection tv, you are probably in the first two cases, both require part replacements and repair job.
If the spots are faint blue, green or pink shadows, then it can be a problem with the anti polarization panel placed on top of the LCD.
Similar spots (colored shadows) may be caused by a problem with the light engine, in that case the fix will be expensive.
If the spots are bright lights, like an aura, that is a problem with the color wheel.
Problems on the light tunnel can cause static gray shadows.
If the spots are static dark stains than that is lcd liquid, the LCD panel must be replaced.