What Is The Cure For The Swollen Lymph Node Between The Neck And Shoulder?

my boyfriend has a swollen lymph node between his neck and left shoulder area. He said it just appeared one day about 5 years ago during a drive from Mississippi to Illinois. It is painful at time but after a good massage for a couple of day the pain subsides. We went to the doctor about a year ago and was told not to worry about it that if his only symptom is occassional pain he was ok. He said it had grown in size within a month or so of his initial discovery but has not appeared to have grown since. When it is not inflammed it actually seems to feel and look smaller in size, but when it flares up it becomes tender, swollen, and painful often in the neck, shoulder, and left armpit area. He also complains of some discomfort in the subclavicular reigon and shooting pain down his left arm during the flare up of the lymph node. Should we be concerned? Should he see another phyisian or get some type of diagnostic test?