Good question, jdriggs, but probably better placed in the infectious disease forums here at MedHelp. Let me explain.
This lump you feel is consistent with a lymphatic gland, part of the human lymphatic system partially responsible for maintaining homeostasis in the body.
The lymph is a clear fluid that circulates throughout the lymphatic system, containing many infection fighting antibodies and associated cells. Lymph is filtered in the lymphatic glands, which are numerous in the neck upper chest, and in the groin.
When your body is fighting an infection, you might notice a slight bump in these locations. Sometimes these glands themselves become overloaded and infected. In this case they become hard, painful, and hot, and that usually indicates that you would benefit from medical attention, especially if accompanied by a fever.
There are many reasons why you may have an enlarged lymphatic gland -- ear infection, sinus infection, tooth infection, etc. Often they indicate the onset of a flu or the common cold.
If this is indeed an enlarged lymphatic gland, there is nothing to worry about and nothing to do. If the gland becomes bothersome, usually a warm pack applied to the gland, with some acetaminophen will ease the discomfort.
Many people swear that vitamin C helps fight infection. This theory was proposed by Nobel winning chemist Dr. Linus Pauling (whom I once had the pleasure of meeting in his Palo Alto California office). Pauling was a great chemist and humanitarian, but his theories regarding vitamin C have proved to be false.
If we can be of further help, please post again. Otherwise, visit some of our other forums:
Infectious Disease:
http://www.medhelp.org/forums/Infectious-Diseases/show/338
and Ear Nose and Throat:
http://www.medhelp.org/forums/Ear--Nose--Throat/show/70