Hi, Based on the symptoms you have described, here are a few possibilities -Muscle knot, Hemangioma, Cyst, Tumor, A muscle knot is commonly seen over the shoulder, trapezius muscle, and other muscles in the area. This can swell and appear as a knot. Rarely, the swelling may increase in size as the injury persists. Usually, the swelling reduces with icing and this can be used to confirm the cause. A hemangioma is blood filled swelling. It may be connected to blood vessels and this can continue to increase in size as the hemangioma swells up with more blood entering the swelling. Hemangiomas are usually treated with surgery or procedures to help stop more blood from filling in. It would be good to discuss this with a surgeon to get to the cause. A cyst or an abscess is a swelling that is seen with infection over the area. This causes an inflammation wall to build around the infection or foreign body. With time, pus forms and this can become a swelling that increases. A cyst is usually very painful and there may be fever as well. A tumor is a swelling that is seen when there is an overgrowth of cells. A tumor can usually be detected very easily with any imaging like an X-ray or Ultrasound. However, in case the symptoms persist or increase, seeing a doctor would be a good idea. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr Vignan Rachabattuni, General & Family Physician