B-cell lymphoma

The B-cell lymphomas are types of lymphoma affecting B cells. Lymphomas are "blood cancers" in the lymph glands. They develop more frequently in older adults and in immunocompromised individuals (such as those with AIDS).

B-cell lymphomas include both Hodgkin's lymphomas and most non-Hodgkins lymphomas. They are often divided into indolent (slow-growing) lymphomas and aggressive lymphomas. Indolent lymphomas respond rapidly to treatment and are kept under control (in remission) with long-term survival of many years, but are not cured. Aggressive lymphomas usually require intensive treatments, but have good prospects for a permanent cure.

Prognosis and treatment depends on the specific type of lymphoma as well as the stage and grade. Treatment includes radiation and chemotherapy. Early-stage indolent B-cell lymphomas can often be treated with radiation alone, with long-term non-reoccurrence. Early-stage aggressive disease is treated with chemotherapy and often radiation, with a 70-90% cure rate. Late-stage indolent lymphomas are sometimes left untreated and monitored until they progress. Late-stage aggressive disease is treated with chemotherapy, with cure rates of over 70%.

Types
There are fourteen kinds of lymphomas involving B cells.

Common
Five account for nearly three out of four patients with non-Hodgkin lymphoma:


 * Diffuse large B cell lymphoma
 * Follicular lymphoma
 * Mucosa-Associated Lymphatic Tissue lymphoma (MALT)
 * Small cell lymphocytic lymphoma (overlaps with Chronic lymphocytic leukemia)
 * Mantle cell lymphoma (MCL)

Rare
The remaining nine are much less common:
 * Burkitt lymphoma
 * Mediastinal large B cell lymphoma
 * Waldenström macroglobulinemia
 * Nodal marginal zone B cell lymphoma (NMZL)
 * Splenic marginal zone lymphoma (SMZL)
 * Intravascular large B-cell lymphoma
 * Primary effusion lymphoma
 * Lymphomatoid granulomatosis

Other
Additionally, some researchers separate out lymphomas that appear result from other immune system disorders, such as AIDS-related lymphoma.

Classic Hodgkin's lymphoma and nodular lymphocyte predominant Hodgkin's lymphoma are now considered forms of B-cell lymphoma.

Associated chromosomal translocations
Chromosomal translocations involving the immunoglobulin heavy locus (IGH@) is a classic cytogenetic abnormality for many B-cell lymphomas, including follicular lymphoma, mantle cell lymphoma and Burkitt's lymphoma. In these cases, The immunoglobulin heavy locus forms a fusion protein with another protein that has pro-proliferative or anti-apoptotic abilities. The enhancer element of the immunoglobulin heavy locus, which normally functions to make B cells produce massive production of antibodies, now induces massive transcription of the fusion protein, resulting in excessive pro-proliferative or anti-apoptotic effects on the B cells containing the fusion protein. In Burkitt's lymphoma and mantle cell lymphoma, the other protein in the fusion is c-myc (on chromosome 8) and cyclin D1 (on chromosome 11), respectively, which gives the fusion protein pro-proliferative ability. In follicular lymphoma, the fused protein is Bcl-2 (on chromosome 18), which gives the fusion protein anti-apoptotic abilities.