What causes knot in the arm which is growing in size and has a bruise?
Patient: My son has a knot that started small on his left upper arm (the under side) the knot has grown in size and now has a large bruise around it. He plays football and has started weight lifting and the knot has become very painful. What could be the cause of the knot? Doctor: Hi, It could be hemangioma, get your MRI done to know exactly the cause of the swelling. Hope I have answered your question. Let me know if I can assist you further.  Regards, Dr. Jaideep Gaver, Orthopedic Surgeon