I discovered a small lump on the upper part of my butt right b4 u get to the waist. my back goes out from time 2 time in that area. what could this be?

Back mass: I don't know, may be from a lipoma to a sarcoma. I know, you are worried, therefore you should see a Dr. he will examine you and provide an intelligent advice. If you still are unhappy, request surgical removal, if is not large can be done in the office. The tissue will be sent for microscopic examination. The results will be communicated to you, and further therapy done according the histology.