patients who have HIV/AIDS than in those who are not infected.

Lymphoma

The term "lymphoma" refers to about a dozen different types of cancer that are characterized by abnormal, rapidly growing white blood cells in the lymphatic system. Lymphoma can spread through the lymphatic system to almost any part of the body, including the intestines, liver, and brain. Lymphomas generally grow and spread more quickly in patients who have HIV/AIDS than in those who are not infected.

The many different types of lymphoma are generally categorized as either Hodgkin's lymphoma or non-Hodgkin's lymphoma (NHL). Both of these types are considered AIDS-related cancers, although NHL is much more common among patients who have HIV/AIDS. Indeed, it is the second most common AIDS-related cancer. Lymphoma that affects the brain is known as primary CNS (central nervous system) lymphoma.

Lymphatic System

The lymphatic system is a network of thin tubes that, like blood vessels, branch and extend throughout the entire body. A transparent, watery fluid (lymph) flows through the tubes and supplies the body with various disease- and infection-fighting cells. The network is dotted with clusters of lymph nodes, which are small organs where the cells are made and stored.

Other tissues and organs that play a role in making, storing, or filtering the infection-fighting cells include the bone marrow (spongy tissue inside the bones), the spleen (organ in the upper abdomen), the thymus (organ in the chest, beneath the breastbone), and the tonsils.