Bret, congrats on completing your treatments. Had the same problem you had a little earlier. Found mine while shaving and felt the bulge in my neck from the lymph node. As mentioned, the cause is not near as important as the after affects and how I deal with it. At least to me. I don't have the knowledge or skills to contribute to a cure, so all I can do is try to help others deal with the present and future. Know that there are a lot of folks on this board who are rooting for your continued improvement as you recover from this disease and look forward to your input to those who follow and those of us who have been here for a while.