I have a small raised lesion about 1mm in size on the edge of the tongue next to lingual tonsil. what could it be. different from look of papillae?

Too small to worry: It is hard to know if a one mm lesion is anything significant. So it should be watched for the next 1 to 2 months for any changes. More than likely it will go away by itself. In the unlikely possibility, it could grow in size which will require a closer monitoring or a possible biopsy to determine its nature. But biopsy is not indicated unless it is >5mm in size. So right now you can relax.