Non-Hodgkin lymphoma (also called non-Hodgkin’s lymphoma or NHL) is cancer that develops in the lymphatic system from cells called lymphocytes, which are a type of white blood cell that helps the body fight infections.
NHL can develop in many parts of the body, including the lymph nodes, bone marrow, spleen, thymus and digestive tract.
NHL is the fifth-most common type of cancer in the United States. It is more common in adults than children. It also tends to be more common in men than women.
The current classification system for non-Hodgkin lymphoma is the WHO/REAL system (World Health Organization/Revised European American Lymphoma classification). The WHO system distinguishes lymphomas based on a number of characteristics, including the microscopic appearance of the cancer cells, the chromosome features of the cells, how the cells group together and the presence of certain chemicals on the surface of the cells.
Non-Hodgkin lymphoma includes all kinds of lymphomas except Hodgkin lymphoma (also known as Hodgkin’s disease), which is marked by the presence of an abnormal lymphocyte called the Reed-Sternberg cell (or B lymphocyte).
There are more than 30 distinct types of non-Hodgkin lymphoma, which can be divided into aggressive (fast-growing or high grade) or indolent (slow-growing or low grade) types.
NHL is further divided according to the cell type involved. There are two main types of lymphocytes: B-lymphocytes (or B cells) and T-lymphocytes (or T cells). Most types of non-Hodgkin lymphomas develop from B cells.
Some forms of B-cell NHL include: diffuse large B-cell lymphoma, follicular lymphoma, Burkitt lymphoma, immunoblastic large cell lymphoma, precursor B-lymphoblastic lymphoma and mantle cell lymphoma.
Some forms of T-cell NHL include: mycosis fungoides, anaplastic large cell lymphoma, peripheral T-cell lymphoma and precursor T-lymphoblastic lymphoma