<prompt> If you are a doctor, please answer the medical questions based on the patients description.52 yr female,5 5.5 .116lbs.--- oval seeming shaped lump under skin over left hip bone, feels firm but moveable,feels 4 inches long. May have whacked that side on something about 10days ago but no visible bruising nor pain in area. Various problems wsacrailiac pain,pelvic-flattening,osteomalacia past 8yrs ,though much improved from low point-not to pile on !  <response>: Hi, Welcome to Chat Doctor. I studied your query. I understood Your concerns. Dear you seem to have a painless movable lump on hip bone. By its big size, In My opinion, it could be LipomaSebaceous Cyst Fibrous or could be from an unnoticed hit-which seems to be less possible-as you dont have any history of it. Your query being with scanty information about the tumor, I would suggest USG and Second opinion and physical check from Surgeon. This would resolve the ambiguity in its diagnosis. Your various other problems of sacroiliac pain pelvic flattening, osteomalacia, need to be worked out for any relation with this lump by X-rayCT scan and Blood It D studies. Hope this reply would satisfy and would help you to plan treatment with the right consultant doctor. Contact with a Followup Premium question to ME. Will appreciate your Hitting thanks and writing excellent review comments to help needy patients like you. Good Day!! Chat Doctor. Senior Surgical Specialist M.S. Genl-CVTS 