foundation concealer you can get very good concealers these days
There are many products and creams on the market - but the natural way to go is to buy plain yogurt and mix it with plain sugar and apply a little every morning. Leave it on for at least an hour. Stay out of the sun as much as you can. It should lighten the spot a little at a time and should be gone by 4 weeks. It's slow, but natural. Better than those bleaching creams that burn your skin.