Lymphoma, or non-Hodgkin lymphoma, is a form of cancer of the immune system called the lymph system which is the disease-fighting network spread throughout the body. In lymphoma, the tumors develop from lymphocytes — a type of white blood cell.
When these white blood cells, called T cells or B cells, become abnormal, the cell divides again and again, making more and more abnormal cells. In a healthy body, the lymphocytes go through a predictable life cycle—old lymphocytes die and the body creates new ones to replace them. However, in lymphoma since the lymphocytes don’t die and instead continue to grow and divide, an oversupply of lymphocytes crowds into the lymph nodes, eventually causing them to swell.
Although the exact cause of Lymphoma is not known, it usually begins in either the B cells or T cells. Most non-Hodgkin’s Lymphoma arises from B cells, which fight infection by producing antibodies that neutralize foreign invaders.
Lymphoma occurs less often in T cells, which are involved in killing foreign invaders directly. Whether the Lymphoma occurs in the B cells or T cells is a crucial factor in determining treatment options.
The disease often spreads to other parts of the lymphatic system including lymphatic vessels, tonsils, adenoids, spleen, thymus and bone marrow.
Some factors that may increase the risk of non-Hodgkin’s lymphoma include:
- Medications that suppress the immune system.
- Infection with certain viruses and bacteria such as HIV and Epstein-Barr virus. Bacteria linked to an increased risk of lymphoma include the ulcer-causing Helicobacter pylori.
- Certain chemicals, such as those used to kill insects and weeds, may increase the risk of developing lymphoma.
- Although Lymphoma is among the most common cancers in childhood, more than 95 percent of cases occur in adults, after the age of 60.
In addition to a complete medical history the diagnostic procedures for non-Hodgkin lymphoma will typically include a physical examination to determine the size and condition of the lymph nodes and to find out whether the liver and spleen are enlarged. Some blood and urine tests apart from some specialized imaging tests might also be ordered. The doctors might also order some biopsy procedures for a more accurate diagnosis.
Although treatment for non-Hodgkin lymphoma will be determined on the basis of age, overall health, and medical history, it will typically include the following components:
- Radiation therapy
- Biologic (immune) therapy
- High-dose chemotherapy with bone marrow or peripheral blood stem cell transplantation
In order to diagnose Lymphoma the following procedures might be ordered:
Lymph node biopsy: This is performed to remove tissue or cells from lymph nodes in the body for examination under a microscope.
Bone marrow aspiration and/or biopsy: This involves taking a small amount of bone marrow fluid (aspiration) and/or solid bone marrow tissue (called a core biopsy), usually from the hip bones, to be examined for the number, size, and maturity of blood cells and/or abnormal cells. This may be done to see if the lymphoma has reached the bone marrow.
X-ray of the chest: This test uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film. It helps determine if the lymphoma has spread to lymph nodes in the chest.
Computed tomography scan (CT or CAT scan): This procedure uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs.
Magnetic resonance imaging (MRI): MRIs use radio waves and magnets. The energy from the radio waves creates patterns formed by different types of tissue and diseases. This produces detailed cross-sectional pictures that look like slices of the body.
Ultrasound (Sonography): A imaging technique which uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels.
Positron emission tomography (PET): A type of nuclear medicine procedure which involves injection of a small amount of radioactive glucose. Glucose use is a sign of active, quickly dividing cells, such as lymphoma. The images from a PET scan show areas of increased cellular activity anywhere in the body.