I have had permanently swollen glands on the right side of my neck for nearly 15 years. They have always remained the same size but two are most prevalent. I have smaller hard one that I can move with my fingers and even slightly pick up and when I release it it makes a hollow popping sounds. The other is slightly bigger, but I can squeeze it and it breaks up into smaller bits, but when released forms straight back together. I have has this for fifteen years now. Should I be concerned in anyway?