The term lymphoma describes several similar types of cancers that result from malignant growth of lymphocytes, which are specialized cells of the immune system. Cancer results when the lymphocytes either multiply too fast or fail to die when they are supposed to. The result is an uncontrolled increase in the number of lymphocytes, which can grow into tumors and cause other complications. Because lymphocytes are found in many parts of the body, different areas of the body can develop lymphomas.
Lymph Nodes
Lymph nodes are small, bean-shaped organs distributed throughout the body, especially in the groin, neck and armpits. They serve as the forward operating stations of the immune system, housing lymphocytes and filtering lymph fluid. Because many of the body's lymphocytes are found in the lymph nodes, they are common sites where lymphoma develops, explains the National Cancer Institute. As the lymphocytes grow out of control, the lymph nodes usually swell. As a result, swollen lymph nodes are one of the first signs of lymphoma.
Spleen
The spleen is another organ that plays an important role in the immune system. Some types of lymphocytes and other immune cells are produced in the spleen, and they are sometimes stored there until needed at a later time. Many different types of lymphomas can develop in the spleen, and an enlarged spleen is another early symptoms of lymphoma, the Lymphoma Research Foundation explains.
Thymus
Lymphocytes are made up of two types of cells---B cells and T cells---which serve different functions. Most of the T cells in the body are made in the thymus, a small organ found in the middle of the chest underneath the breast bone. Some rare cases of T-cell lymphoma begin in the thymus. This type of T-cell lymphoma is most common in young adults, when the thymus is very active, and young males are more often affected than females, according to the American Cancer Society.
Bone Marrow
The other main type of lymphocytes, the B cells, are primarily produced in bone marrow. Bone marrow is the spongy tissue that is found in the hollow cores of bones. In addition to B cells, bone marrow also produces blood cells. If the B lymphocytes turn malignant and start growing uncontrollably, this can cause lymphoma, explains the American Cancer Society. A different type of cancer called leukemia can also develop in bone marrow. Leukemia is caused by blood cells growing out of control, instead of the lymphocytes.
Skin
Sometimes, T lymphocytes that are malignant can affect the skin, causing a type of lymphoma known as cutaneous T-cell lymphoma, the Stanford Medicine Cancer Center explains. Cutaneous T-cell lymphomas can cause tumors to grow on the skin, which may sometimes turn into open sores or ulcers.
Other Organs
In other cases, lymphoma can spread to several different organs throughout the body, reports the Lymphoma Support and Research Association of Australia. The lungs and liver can become sites of lymphoma. Some mucosal linings of the body, such as the inside of the nose, stomach and lungs, may also develop lymphomas. The brain, spinal cord or the fluid surrounding them, known as cerebrospinal fluid, are also sites that can develop lymphoma.
