In non-Hodgkin's lymphoma (NHL), white blood cells called lymphocytes divide and grow without order or control. The abnormal lymphocytes usually are either B-cell or T-cell lymphocytes. But most cases of NHL involve B-cell lymphocytes.
Lymph tissue is present in many areas of the body, so NHL can start almost anywhere in the body. It may occur in a single lymph node, a group of lymph nodes, or an organ. And it can spread to almost any part of the body, including the liver, bone marrow, and spleen .
NHL may be classified as:
- Slow-growing lymphomas, which spread slowly and cause few symptoms. These may also be called indolent or low-grade lymphomas.
- Fast-growing lymphomas, which spread quickly and cause severe symptoms. These may also be called aggressive lymphomas and may be classified as intermediate-grade or high-grade.
Over time, lymphoma cells may replace the normal cells in the bone marrow. Bone marrow failure results in the inability to produce red blood cells that carry oxygen, white blood cells that fight infection, and platelets that stop bleeding.
Long-term survival depends on the type of non-Hodgkin's lymphoma and the stage of the disease when it is diagnosed. About 80 out of 100 people diagnosed with non-Hodgkin's lymphoma are alive 1 year after the disease is diagnosed. That number drops to about 67 out of 100 at 5 years, and 57 out of 100 at 10 years.1