Non-Hodgkin's lymphoma begins when a lymphocyte becomes abnormal. The abnormal cell divides to make copies. The new cells divide again and again, making more and more abnormal cells. The abnormal cells don’t die when they should. They don’t protect the body from infections or other diseases. The buildup of extra cells often forms a mass of tissue called a growth or tumor.
To understand what Non-Hodgkin's lymphoma is, it helps to know about the lymphatic system. The lymphatic system is part of the immune system and is comprised of:
- Lymph vessels: The lymphatic system has a network of lymph vessels. Lymph vessels branch into all the tissues of the body.
- Lymph: The lymph vessels carry clear fluid called lymph. Lymph contains white blood cells, especially lymphocytes such as B cells and T cells.
- Lymph nodes: Lymph vessels are connected to small, round masses of tissue called lymph nodes. Groups of lymph nodes are found in the neck, underarms, chest, abdomen and groin. Lymph nodes store white blood cells. They trap and remove bacteria or other harmful substances that may be in the lymph.
- Other parts of the lymphatic system: Tonsils, thymus and spleen.
Lymphatic tissue is also found in other parts of the body including the stomach, skin and small intestine.
If a patient has swollen lymph nodes or another symptom that suggests Hodgkin lymphoma, some of the following exams and tests may be completed:
During a physical, a doctor will check for swollen lymph nodes in the neck, underarms, and groin. The physician also checks for a swollen spleen or liver.
Your doctor will have a lab complete a blood count to check the number of white blood cells and other cells and substances.
X-ray pictures may show swollen lymph nodes or other signs of disease in the chest.
A biopsy is the only sure way to diagnose Hodgkin’s lymphoma. The doctor may remove an entire lymph node (excisional biopsy) or only part of a lymph node (incisional biopsy). A thin needle (fine needle aspiration) usually cannot remove a large enough sample for the pathologist to diagnose Hodgkin’s lymphoma. Removing an entire lymph node is best. The pathologist uses a microscope to check the tissue for Hodgkin lymphoma cells. A person with Hodgkin’s lymphoma usually has large, abnormal cells known as Reed-Sternberg cells. They are not found in people with non-Hodgkin’s lymphoma.