Small lump on the gluteus

Hello all,
I have a small (half-pea) sized semi-hard lump on the gluteus. It is just under the skin and visible only by touch, the skin above it is normal. It is immobile and seems to be attached to the underlying tissue. It is painless although there is an itching pain when I sit on very hard services (metal, or cement) while the area around it is perspiring. I've had it for about 3 years and it hasn't changed in any way (size,shape). I've asked the pharmacist and he said that there are 100 reasons that this may be. He said that is should treat it with betadin (iodine) scrub and a antibiotic cream at first and then check for other things. I know that I should probably see a doctor but I would like some opinions first.

Thank you all in advance.