Cause Of Pain Behind Ear Bump Behind Left Ear Causing Massive Pain And Headaches?

Bump behind left ear causing massive pain and headaches? - cause of pain behind ear

Do you know someone who had this bump behind the ear for about 6 months and has grown recently, and begin to large amounts of pain (headache, in particular). I thought it might be lymph nodes, but 6 months is a long time for the swelling as I thought. What is possible?