I have had a mobile Â¼ inch lump on / near my clavicle for the past 2 or so years. I am able to move it on top of my clavicle bone and to what seems to be below the bone into the muscle area. It has not started hurting until recently. I am experiencing pain in my neck, right shoulder, and right arm. I have made an appointment for an ultrasound but I am a little worried because of the new onset of pain. Any ideas what it may be?