Palmrest Material Composition Breakdown?

I recognize how strange this is going to sound, and I’ve never heard of this problem before. Hopefully I can adequately describe the issue I need help with. I have a Latitude E6420 that has not been used, and has been sitting in a cabinet, for over a year untouched. Whatever material the palmrest is composed of, or coated with, appears to have begun breaking down(??). The entire palmrest area is extremely sticky. At first I thought there was something on it, but whatever is causing the problem is not something that will wipe off, and it it affects every millimeter of the palmrest. I have tried using a cloth with Windex, and then with rubbing alcohol, but nothing works. The problem is limited to the palmrest area only, including the volume/mute buttons, but not the keyboard, the touchpad, or even the bezel around the keyboard. The display, and the bezel around the display, are also not impacted. The palmrest must be composed of a different material than the rest of the laptop case. Whatever it is, it does not appear to transfer to my skin or clothing, it just causes my hands stick to the surface really. Has anyone else ever experienced a material composition breakdown like this? If so, how did you resolve it? Does anyone know what causes the material to decompose like that, and is there anything that I can do to get rid of the stickiness of those surfaces? I would sincerely appreciate any help with this, because I can’t use the laptop like this.