Can you show us an image of it. Last time i haev this problem but it was not serious, i wipe out the spot with a spectacles cloth. Unless your screen is damage and you cannot use your laptop then replace the screen, if you can use the laptop but there is a white spot try wiping it away with a cloth. ( No water ) And do this when the laptop is turn off. Why will somone pick up a laptop by holding the screen. it will spoil the screen if you press on the screen too tightly.