Supraclavicular Swelling On The Left Of Neck, Itchy Rash On The Top Of Swelling. Labs Tests Normal. Lymphoma Chances?

Hi, I have supraclavicular swelling on the left side of my neck/ clavicle . I have had this for six weeks and there is a rash on top of the swollen area that is very itchy. The swelling has now started, a little, on the right side with a bit of the same rash. I went to my dr and the blood tests she did are normal, although liver enzymes are at the high end of normal. I have an ultrasound booked but not until the end of the month (three weeks away). She is concerned about lymphoma , my grandfather died from NHL. Can you please tell me if there is any chance that this is caused by a benign source? I am really concerned as I am a mother of two children. In addition, I now have noticed a small lump on my left hand and a pretty consistent pain in the middle of my back on my left side. Thanks, in advance for your help.