Hello, I have a deep, hard movable lump in my upper armpit. I ve had this for about a year now, but am starting to get pain running from the lump in a line down my arm, aswell as some discomfort in the area where the lump is. The discomfort is now and again, not all the time. An ultrasound scan just showed blood vessels. What could this be and should I persue to get an answer?