This is a wart. It is on the outside of my first knuckle, is circular, about 3 mm, has the typical "beaded" appearance of a wart. It is not pigmented, nor is it rough, but it is definitely not scar tissue or a mole, either. It is one of several on that hand, the rest being small, pinhead-sized, and in an irregular group on the heel of my hand. I can't remember when they weren't there.
Liz
