What is the largest mass of lymphoid tissue in the body?

The spleen is the largest mass of lymphoid tissue in the body, serving multiple essential functions within the immune system. It acts as a blood filter, removing old or damaged red blood cells, and is also involved in the production of white blood cells, specifically lymphocytes, which are crucial for the immune response. Additionally, the spleen stores blood and helps to fight off infections by producing antibodies and filtering out pathogens from the bloodstream.

While lymph nodes, tonsils, and the thymus are important components of the lymphatic system, they are smaller in size compared to the spleen. Lymph nodes serve as filtering stations throughout the lymphatic system, tonsils help protect against pathogens entering through the mouth and nose, and the thymus is primarily involved in the maturation of T-lymphocytes. Thus, none of these structures match the spleen's size or comprehensive role in both blood filtration and immune response.