There are two types of lymph node cancer – primary and secondary. When the cancer starts in a lymph node or spreads to it from adjacent lymph nodes it is known as primary lymph node cancer or a lymphoma. If the cancer originates in some other organ or tissue and then spreads to the lymph nodes it is known as secondary or metastatic lymph node cancer. Malignant lymph nodes may be felt as firm or hard, immobile (fixed) swollen lumps which are most often painless and may sometimes be matted together.
Primary lymph node cancer or lymphoma can be divided into two types – Hodgkin’s lymphoma and non-Hodgkin lymphoma. These lymphomas may be further divided into various sub-types.
The importance of secondary lymph node involvement in various types of cancer lies in the fact that it indicates spread of cancer away from the primary site as well as helping to determine the prognosis of the disease, chances of recurrence and the treatment plan.
The Lymphatic System
The lymphatic system is an important part of the body’s immune system – the natural defense mechanism against infections. It is comprised of the bone marrow, spleen, thymus, tonsils and lymph nodes which are all connected together by a network of lymphatic vessels that contain a clear fluid called lymph or lymphatic fluid.
The lymph nodes are small round or oval glands which act as filters to trap bacteria, viruses and other waste materials. These microorganisms are then destroyed by the lymphocytes present within the lymph nodes. The lymphatic fluid is then returned to the circulation.
Lymph nodes are located all over the body and the nodes that are most easily palpated (felt by touch) may be found in the armpit (axillary), neck (cervical), and groin (inguinal). The other important lymph nodes are situated in the chest (mediastinal), abdomen (retroperitoneal or mesenteric), and the pelvis (pelvic).
Lymph Node Swelling
Lymph node swelling may occur for a number of reasons and cancer of the lymph node should not be the first diagnosis if swollen lymph nodes are present. The lymph nodes of the armpit, neck and groin are the most prone to swelling. Refer to the following articles for further information on :
- Causes of swollen armpit lymph nodes
- Causes of swollen groin lymph nodes
- Causes of swollen neck lymph nodes
In primary lymph node cancer (lymphoma), the cells of the lymph nodes become cancerous and the cancer is usually restricted to the lymph nodes. In secondary lymph node cancer, the cancer has spread from a malignant tumor occurring in an organ or tissue elsewhere in the body (metastasis). Refer to the following articles for more information on lymph node cancers :