What is the lymphatic system?

Neck masses in children often involve the lymphatic system, which is part of the immune system and functions to fight disease and infections. The lymphatic system goes through many changes throughout a child's growth and development. Before birth, a fetus relies on the mother's immune system for protection from infections. At birth, a newborn's lymphatic system begins to respond to the frequent exposure to new antigens (organisms and diseases). Lymphatic tissue grows steadily until puberty, when growth slows.

The lymphatic system includes the following:

• Lymph. Fluid containing lymphocyte cells.
• Lymph vessels. Thin tubes that carry lymph fluid throughout the body.
• Lymphocytes. White blood cells that fight infection and disease.
• Lymph nodes. Bean-shaped organs, found in the underarm, groin, neck, chest, and abdomen, that act as filters for the lymph fluid as it circulates through the body.

Children are constantly fighting off new germs and infections and their lymphatic system quickly responds to these antigens. Because of this response, it is quite common for children to have slightly enlarged lymph nodes in certain areas of the body some of the time. However, changes in the lymph nodes can also indicate certain conditions or diseases that need special treatment. Always consult your child's doctor for questions or concerns about any mass you notice in your child.

The lymphatic system plays a crucial role in immune function and in the delivery of vital nutrients to the body. Functioning almost like a sponge, the lymphatic system absorbs excess lymph fluid — watery fluid containing protein, electrolytes, cells and other substances — from the body’s organs and returns it to the blood stream.