Lymphoma reference

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Lymphoma is a type of solid neoplasm that originates in lymphocytes (a type of white blood cell in the vertebrate immune system). This is in contrast to lymphoid leukemia, which is a malignancy of circulating cells.[1]

There are many types of lymphoma. Lymphomas are part of the broad group of diseases called hematological neoplasms.

In the 19th and 20th centuries the affliction was called Hodgkin's Disease, as it was discovered by Thomas Hodgkin in 1832. Colloquially, lymphoma is broadly categorized as Hodgkin's lymphoma and non-Hodgkin lymphoma (all other types of lymphoma). Scientific classification of the types of lymphoma is more detailed.

Although older classifications referred to histiocytic lymphomas, these are recognized in newer classifications as of B, T or NK cell lineage. Histiocytic malignancies are rare and are classified as sarcomas

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Prevalence

According to the U.S. National Institutes of Health, lymphomas account for about five percent of all cases of cancer in the United States, and Hodgkin's lymphoma in particular accounts for less than one percent of all cases of cancer in the United States.

Because the whole system is part of the body's immune system, patients with a weakened immune system, such as from HIV infection or from certain drugs or medication, also have a higher incidence of lymphoma.

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Classification



The WHO Classification, published in 2001[2], is the latest classification of lymphoma and is based on the "Revised European-American Lymphoma classification" (REAL). This system attempts to group lymphomas by cell type, i.e., the normal cell type that most resembles the tumor. There are three large groups: the B cell, T cell, and natural killer cell tumors. Other less common groups, including Hodgkin lymphoma, are also recognized. (ICD-O codes are provided where available.)

[edit] Mature B cell neoplasms
DNA-microarray analysis of Burkitt's lymphoma and diffuse large B-cell lymphoma (DLBCL) showing differences in gene expression patterns. Colors indicate levels of expression; green indicates genes that are underexpressed in lymphoma cells (as compared to normal cells), whereas red indicates genes that are overexpressed in lymphoma cells.
DNA-microarray analysis of Burkitt's lymphoma and diffuse large B-cell lymphoma (DLBCL) showing differences in gene expression patterns. Colors indicate levels of expression; green indicates genes that are underexpressed in lymphoma cells (as compared to normal cells), whereas red indicates genes that are overexpressed in lymphoma cells.

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o Chronic lymphocytic leukemia/Small lymphocytic lymphoma
o B-cell prolymphocytic leukemia
o Lymphoplasmacytic lymphoma (such as Waldenström macroglobulinemia)
o Splenic marginal zone lymphoma
o Plasma cell neoplasms
+ Plasma cell myeloma
+ Plasmacytoma
+ Monoclonal immunoglobulin deposition diseases
+ Heavy chain diseases
o Extranodal marginal zone B cell lymphoma, also called MALT lymphoma
o Nodal marginal zone B cell lymphoma (NMZL)
o Follicular lymphoma
o Mantle cell lymphoma
o Diffuse large B cell lymphoma
o Mediastinal (thymic) large B cell lymphoma
o Intravascular large B cell lymphoma
o Primary effusion lymphoma
o Burkitt lymphoma/leukemia

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Mature T cell and natural killer (NK) cell neoplasms

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o T cell prolymphocytic leukemia
o T cell large granular lymphocytic leukemia
o Aggressive NK cell leukemia
o Adult T cell leukemia/lymphoma
o Extranodal NK/T cell lymphoma, nasal type
o Enteropathy-type T cell lymphoma
o Hepatosplenic T cell lymphoma
o Blastic NK cell lymphoma
o Mycosis fungoides / Sezary syndrome
o Primary cutaneous CD30-positive T cell lymphoproliferative disorders
+ Primary cutaneous anaplastic large cell lymphoma
+ Lymphomatoid papulosis
o Angioimmunoblastic T cell lymphoma
o Peripheral T cell lymphoma, unspecified
o Anaplastic large cell lymphoma

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Hodgkin lymphoma

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o Nodular lymphocyte-predominant Hodgkin lymphoma
o Classical Hodgkin lymphoma
+ Nodular sclerosis
+ Mixed cellularity
+ Lymphocyte-rich
+ Lymphocyte depleted or not depleted

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Immunodeficiency-associated lymphoproliferative disorders

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o Associated with a primary immune disorder
o Associated with the Human Immunodeficiency Virus (HIV)
o Post-transplant
o Associated with Methotrexate therapy

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Working formulation

The Working Formulation, published in 1982, is primarily descriptive. It is still occasionally used, but has been superseded by the WHO classification, above.

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Low grade

* Malignant Lymphoma, small lymphocytic (chronic lymphocytic leukemia)
* Malignant Lymphoma, follicular, predominantly small cleaved cell
* Malignant Lymphoma, follicular, mixed (small cleaved and large cell)

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Intermediate grade

* Follicular Large Cell
* Diffuse small cleaved cell
* Diffuse mixed small and large cell
* Diffuse large cell

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High grade

* Malignant Lymphoma, large cell, immunoblastic
* Malignant Lymphoma, lymphoblastic
* Malignant Lymphoma, small non-cleaved cells (Burkitt's lymphoma)

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