Anus problem?

Patient: I have a swelled lumpbump around my anus. Its the same color as the rest of it, and it dosnt hurt. Ive had it for about a uear and a half, qnand i just want to know if it could be somethung serious. It dosnt seem to effect me in any way, except im self concious about it. Im in my teens, and its almost .5 in long.