What Should We Do Next For Persistent Golf-ball-sized Swelling Above The Collarbone?

my husband has swelling just above his collarbone. it is about the size of a golf ball. the nurse practitioner we saw at urgent care told him to see is family doctor but she was going to order an ultrasound. She thought it was a swollen lymph node. we seen his family care physician the next day and he thinks it is muscular. we had a ct scan without contrast. it came back normal and so did his bloodwork. the swelling is still there has been 12 days now and i am very concerned. what should we do