B-cell lymphoma

The B-cell lymphomas are types of lymphoma affecting B cells. Lymphomas are "blood cancers" in the lymph nodes. They develop more frequently in older adults and in immunocompromised individuals.
B-cell lymphomas include both Hodgkin's lymphomas and most non-Hodgkin lymphomas. They are typically divided into low and high grade, typically corresponding to indolent lymphomas and aggressive lymphomas, respectively. As a generalisation, indolent lymphomas respond to treatment and are kept under control with long-term survival of many years, but are not cured. Aggressive lymphomas usually require intensive treatments, with some having a good prospect 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-recurrence. 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 numerous kinds of lymphomas involving B cells. The most commonly used classification system is the WHO classification, a convergence of more than one, older classification systems.

Common

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

Diffuse large B-cell lymphoma
Follicular lymphoma
Marginal zone B-cell lymphoma or mucosa-associated lymphatic tissue lymphoma
B-cell [chronic lymphocytic leukemia|Small lymphocytic lymphoma]
Mantle cell lymphoma

Rare

The remaining forms are much less common:

Other

Additionally, some researchers separate out lymphomas that appear to 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.

Diagnosis

When a person appears to have a B-cell lymphoma, the main components of a workup are:

Establishing the precise subtype: Initially, an incisional or excisional biopsy is preferred. A core needle biopsy is discouraged except in case a lymph node is not easily accessible. Fine-needle aspiration is only acceptable in selected circumstances, in combination with immunohistochemistry and flow cytometry.
Determining the extent of the disease
The person's general health status.

	Follicular lymphoma	Marginal zone B-cell lymphoma or mucosa-associated lymphatic tissue (MALT) lymphoma	Small lymphocytic lymphoma / chronic lymphocytic leukemia	Mantle cell lymphoma
CD5	-	-	+	+
CD10	+	-	-	-
CD23	-	-	+	-
Cyclin D1	-	-	-	+

Associated chromosomal translocations

s involving the immunoglobulin heavy locus 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 and cyclin D1, respectively, which gives the fusion protein pro-proliferative ability. In follicular lymphoma, the fused protein is
Bcl-2, which gives the fusion protein anti-apoptotic abilities.