Lymphoma

history

- | , ICD9 = | , ICDO = 9590-9999 | , OMIM = | , MedlinePlus = | , eMedicineSubj = | , eMedicineTopic = | , MeshID = D008223 | }}

Lymphoma is a cancer that begins in the lymphocytes of the immune system and presents as a solid tumor of lymphoid cells. It is treatable with chemotherapy, and in some cases radiotherapy and/or bone marrow transplantation, and can be curable, depending on the histology, type, and stage of the disease. These malignant cells often originate in lymph nodes, presenting as an enlargement of the node (a tumor). Lymphomas are closely related to lymphoid leukemias, which also originate in lymphocytes but typically involve only circulating blood and the bone marrow (where blood cells are generated in a process termed haematopoesis) and do not usually form static tumors. There are many types of lymphomas, and in turn, lymphomas are a part of the broad group of diseases called hematological neoplasms.

Thomas Hodgkin published the first description of lymphoma in 1832, specifically of the form named after him, Hodgkin's lymphoma. Since then, many other forms of lymphoma have been described, grouped under several proposed classifications. The 1982 Working formulation classification became very popular. It introduced the category non-Hodgkin lymphoma (NHL), divided into 16 different diseases. However, because these different lymphomas have little in common with each other, the NHL label is of limited usefulness for doctors or patients and is slowly being abandoned. The latest classification by the WHO (2001) lists 43 different forms of lymphoma divided in four broad groups.

Some forms of lymphoma are categorized as indolent (e.g. small lymphocytic lymphoma), compatible with a long life even without treatment, whereas other forms are aggressive (e.g. Burkitt's lymphoma), causing rapid deterioration and death. However, most of the aggressive lymphomas respond well to treatment and are curable. The prognosis therefore depends on the correct classification of the disease, established by a pathologist after examination of a biopsy.Wagman LD. »"Principles of Surgical Oncology" in Pazdur R, Wagman LD, Camphausen KA, Hoskins WJ (Eds) »Cancer Management: A Multidisciplinary Approach. 11 ed. 2008.

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

Classification

A number of different classification systems exist for lymphoma. As an alternative to the American Lukes-Butler classification, in the early 1970s, Karl Lennert of Kiel, Germany, proposed a new system of classifying lymphomas based on cellular morphology and their relationship to cells of the normal peripheral lymphoid system.

REAL

In the mid 1990s, the Revised European-American Lymphoma (REAL) Classification attempted to apply immunophenotypic and genetic features in identifying distinct clinicopathologic entities among all the lymphomas except Hodgkin's lymphoma.www.emedicine.com on Lymphoma, Non-Hodgkin REAL has been superseded by the WHO classification.

WHO

The WHO Classification, published in 2001 and updated in 2008, is the latest classification of lymphoma and is based upon the foundations laid within 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) and defining phenotypic, molecular or cytogenetic characteristics. There are three large groups: the B cell, T cell, and natural killer cell tumors. Other less common groups, are also recognized. Hodgkin's lymphoma, although considered separately within the WHO (and preceding) classifications, is now recognized as being a tumor of, albeit markedly abnormal, lymphocytes of mature B cell lineage.

Mature B cell neoplasms

Mature T cell and natural killer (NK) cell neoplasms

Hodgkin lymphoma

  • Classical Hodgkin lymphomas:
    • Nodular sclerosis
    • Mixed cellularity
    • Lymphocyte-rich
    • Lymphocyte depleted or not depleted
  • Nodular lymphocyte-predominant Hodgkin lymphoma

Immunodeficiency-associated lymphoproliferative disorders

  • Associated with a primary immune disorder
  • Associated with the Human Immunodeficiency Virus (HIV)
  • Post-transplant
  • Associated with methotrexate therapy
  • Primary central nervous system lymphoma occurs most often in immunocomprimised patients,in particular those with AIDS,but it can occur in the immunocompetent as well.It has a poor prognosis,particulary in those with AIDS.Treatment can consist of corticosteroids,radiotherapy,and chemotherapy,often with methotrexate.

Working Formulation and Non-Hodgkin lymphoma

The 1982 Working Formulation is a classification of non-Hodgkin lymphoma. It excluded the Hodgkin's lymphomas and divided the remaining lymphomas (currently numbering 39 distinct diseases) into four grades (Low, Intermediate, High, and Miscellaneous) related to prognosis, with some further subdivisions based on the size and shape of affected cells. Because the most sophisticated technology used in diagnostic work at the time was the simple light microscope, it included no information about cell surface markers, or genetics, and it made no distinction between T-cell lymphomas or B-cell lymphomas.

The Working Forumulation was superseded by REAL, which in turn has since been replaced by the WHO in 2001 (updated in September 2008), but it is still used by cancer agencies for compilation of lymphoma statistics and historical comparisons. The Working Formulation is obsolete, as is the term non-Hodgkin lymphoma.

Other classification systems

Symptoms

Diagnosis, etiology, staging, prognosis, and treatment

 Depends on the specific form of lymphoma. For low-grade lymphoma, watchful waiting is often the initial course of action. If a low-grade lymphoma is becoming symptomatic, radiotherapy or chemotherapy are the treatments of choice, as while they do not cure the lymphoma, they can palliate symptoms, particulary painful lymphadenopathy. Patients with low-grade lymphoma can live near-normal lifespans, but the disease is incurable. Treatment of high-grade lymphoma can result in a cure in the majority of cases, however, the prognosis for patients with a poor response to therapy is worse. Treatment for high-grade lymphoma typically consists of aggressive chemotherapy, including the CHOP regimen. Hodgkin lymphoma typically is treated with radiotherapy alone, as long as it is localized. Advanced Hodgkins disease requires systemic chemotherapy, sometimes combined with radiotherapy. See the article on the corresponding form of lymphoma for further information.

Epidemiology

death from lymphomas and multiple myeloma per 100,000 inhabitants in 2004.

]] Lymphoma is the most common form of hematological malignancy, or "blood cancer", in the developed world.

Taken together, lymphomas represent 5.3% of all cancers (excluding simple basal cell and squamous cell skin cancers) in the United States, and 55.6% of all blood cancers.

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.

See also

References

External links

home | This article is licensed under the GNU Free Documentation License. See full license termsIt uses material from the Wikipedia article "lymphoma ". | compliance | March 20th 2010