I found a lump in my left upper armpit nearly 12 months ago. I thought it had been caused by my new deodorant which had irritated my skin & made me scratch. I waited for four weeks to see if it went down, but when it didn't, I made an appointment to see my GP. He wasn't sure about it, so booked me a breast clinic appointment. A few weeks later, I had a mammogram, an ultrasound & a breast exam. Nothing was found, only slightly dense breast tissue & they measured the lymph nodes in my armpit. Doctor said it may have been caused by the deodorant & would take up to eight weeks to even start going down. So, here I am, nearly a year later & the lump is still there. Same size. I can move it around. It seems quite rubbery. No pain. No marks. Sebaceous cysts run in my Dad's family. I also have a tiny one above my buttock. What do I do? Go back to get it re-assessed? I don't want to waste anyone's time. Would they do a biopsy to see what it's made up of? I would appreciate any advice. Thankyou!