Types of NHL
Throughout the past 40 years, the classification of lymphoma has changed considerably. These changes have been based upon new insights provided by technological advances, as well as advances in our understanding of the clinical behavior of lymphoma.
Like Hodgkin's disease, non-Hodgkin's lymphoma is composed of a very mixed group of cancers. There are many subtypes, each with a different prognosis. The loosely divided classifications, as recognized by the International Lymphoma Study Group (ILSG), are:
- Indolent (slow-growing, low grade) lymphomas and lymphoid leukemias
- Moderately aggressive (intermediate grade) lymphomas and lymphoid leukemias
- Aggressive (high grade) lymphomas
- Highly aggressive lymphomas and lymphoid leukemias
NHLs may be separated further according to cell type: B-cell tumors are composed of B-cell variants, while T-cell tumors are composed of T cell. Among NHLs, roughly 85% of cases are B-cell cancers, whereas only 15% are T-cell cancers.
In the normal immune system, B-cells (B-lymphocytes) fight bacteria by developing into plasma cells. The plasma cells make antibodies that "tag" germs for removal by specialized immunologic cells which surround and digest them. By contrast, T-cells (T lymphocytes) are immunologic "conductors." They direct B-cells and other lymphatic cells in the production of an overall immune response. T-cells help to rid the body of viruses, fungi, and certain bacteria, and they also make cytokinessubstances that draw other infection-fighting white blood cells to tissues that are under attack by microorganisms.
Table 2: NHL Groups
| Suggested NHL groups recognized by the ILSG: | ||
| I. Slow-Growing Lymphomas and Lymphoid Leukemias | ||
| B-cell |
B-Cell Chronic Lymphocytic Leukemia (B-CLL)/Small Lymphocytic Lymphoma (SLL) |
|
| T-cell |
Large Granular Lymphocyte Leukemia Adult T-Cell Leukemia/Lymphoma (ATL/L ) [smoldering] Mycosis Fungoides/Sézary Syndrome |
|
| II. Moderately Aggressive Lymphomas and Lymphoid Leukemias | |
| B-cell |
B-Cell Prolymphocytic Leukemia (B-PLL) Mantle Cell Lymphoma Follicle Center Lymphoma, Follicular Small Cleaved Cell (FSC), Follicle Center Lymphoma (follicular large cell)
|
| T-cell |
T-cell Chronic Lymphocytic Leukemia/Prolymphocytic Leukemia (T-CLL/PLL) Adult T-Cell Leukemia/Lymphoma (ATL/L) [chronic] Angiocentric Lymphoma Angioimmunoblastic Lymphoma |
| III. Aggressive Lymphomas | ||
| B-cell |
B-Cell Large B-Cell Lymphoma
|
|
| T-cell |
Peripheral T-Cell Lymphomas Intestinal T-Cell Lymphoma Anaplastic Large Cell Lymphoma Sézary Syndrome
|
|
| IV. Highly Aggressive Lymphomas and Lymphoid Leukemias | |
| B-cell |
Precursor B-Lymphoblastic Leukemia/Lymphoma (PB-LBL/L) Burkitt's Lymphoma High-Grade B-Cell Lymphoma, Burkitt's-like
|
| T-cell |
Precursor T-lymphoblastic leukemia/lymphoma (T-LBL/L) Adult T-cell leukemia/Lymphoma (ATLL) [acute and lymphomatous] |
