They are lymph nodes and the condition is called lymphadenopathy. They are part of the immune system's defence workings and commonly swell when the body's fighting infection. It figures that when the immune system is activated in misguided autoimmune disease activity ( fighting our own cells ), they can swell too. It is very common and you'll be hearing from other people no doubt.
I don't know what particular significance it has apart from being quite useful for diagnosis. Maybe a sign of a flare in some people.