I have a brown spot around my belly button that seems to fade when I rub it vigorously with soap and water or rubbing alcohol. I never thought of it before since I've had it for years, but now I'm kinda curious about what it could be. I know its not dirt since I shower every night and I'm kinda doubting its cancer since it fades with scrubbing. I never really worried about it before and just assumed it was a birthmark So, anyone know what this is?