Lymphoma is a cancer in the lymphatic cells 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). It can also affect other organs in which case it is referred to as extranodal lymphoma. Extranodal sites include the skin, brain, bowels and bone. 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.
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.
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 diagnosis and classification of the disease, which is established after examination of a biopsy by a pathologist (usually a hematopathologist).
Working Formulation and non-Hodgkin lymphoma
The 1982
Working Formulation is a classification of
non-Hodgkin lymphoma. It excluded the Hodgkin lymphomas and divided the remaining lymphomas into four grades (Low, Intermediate, High, and Miscellaneous) related to prognosis, with some further subdivisions based on the size and shape of affected cells. This purely histological classification included no information about
cell surface markers, or genetics, and it made no distinction between
T-cell lymphomas or
B-cell lymphomas.
See here
The Working Formulation was widely accepted at the time of its publication but is now obsolete. It was superseded by subsequent classifications (see below) but it is still used by cancer agencies for compilation of lymphoma statistics and historical rare comparisons.
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. REAL has been superseded by the WHO classification.
REAL & WHO
•B-cell neoplasms
–precursor
–mature
•T-cell neoplasms
–precursor
–mature
•Hodgkin lymphomaNon-HodgkinLymphomas
World Health Organization (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
World Health Organization (and preceding) classifications, is now recognized as being a tumor of, albeit markedly abnormal, lymphocytes of mature B cell lineage.
Mature B cell neoplasms
*Chronic lymphocytic leukemia/Small lymphocytic lymphoma
B-cell prolymphocytic leukemia
Lymphoplasmacytic lymphoma (such as Waldenström macroglobulinemia)
Splenic marginal zone lymphoma
Plasma cell neoplasms:
*Plasma cell myeloma
*Plasmacytoma
*Monoclonal immunoglobulin deposition diseases
*Heavy chain diseases
Extranodal marginal zone B cell lymphoma, also called MALT lymphoma
Nodal marginal zone B cell lymphoma (NMZL)
Follicular lymphoma
Mantle cell lymphoma
Diffuse large B cell lymphoma
Mediastinal (thymic) large B cell lymphoma
Intravascular large B cell lymphoma
Primary effusion lymphoma
Burkitt lymphoma/leukemia
Mature T cell and natural killer (NK) cell neoplasms
T cell prolymphocytic leukemia
T cell large granular lymphocytic leukemia
Aggressive NK cell leukemia
Adult T cell leukemia/lymphoma
Extranodal NK/T cell lymphoma, nasal type
Enteropathy-type T cell lymphoma
Hepatosplenic T cell lymphoma
Blastic NK cell lymphoma
Mycosis fungoides / Sezary syndrome
Primary cutaneous CD30-positive T cell lymphoproliferative disorders
*Primary cutaneous anaplastic large cell lymphoma
*Lymphomatoid papulosis
Angioimmunoblastic T cell lymphoma
Peripheral T cell lymphoma, unspecified
Anaplastic large cell lymphoma
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,particularly in those with AIDS.Treatment can consist of corticosteroids, radiotherapy,and chemotherapy,often with methotrexate.
Other classification systems
ICD-O (codes 9590-9999, details at )
ICD-10 (codes C81-C96, details at )
Symptoms
Anorexia
Dyspnea
Fatigue
Fever of unknown origin
Lymphadenopathy
Night sweats
Pruritus
Weight loss
Diagnosis, etiology, staging, prognosis, and treatment
{|class="wikitable" align="right"
!colspan=3|5-year relative survival by stage at diagnosis
|-
! Stage at diagnosis !! 5-year relative
survival (%) !! Percentage
of cases (%)
|-
| Distant (cancer has metastasized) || 59.9 || 45
|-
| Localized (confined to primary site) || 82.1 || 28
|-
| Regional (spread to regional lymphnodes) || 77.5 || 19
|-
| Unknown (unstaged)|| 67.5 || 8
|}
These depend on the specific form of lymphoma. For some forms of 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; although they do not cure the lymphoma, they can alleviate the symptoms, particularly painful
lymphadenopathy. Patients with these types of lymphoma can live near-normal lifespans, but the disease is incurable. Treatment of some other, more aggressive, forms of lymphoma can result in a cure in the majority of cases, but the prognosis for patients with a poor response to therapy is worse. Treatment for these types of 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 articles 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.
Comparison
Following is a comparison of the most common types of lymphoma:
{|class="wikitable"
! Lymphoma type !! Relative
incidence !!
Histopathology !!
Cell markers !! Overall
5-year
survival !! Other comments
|-
!
Precursor T-cell leukemia/lymphoma
| 40% of lymphomas in childhood.
|
Lymphoblasts with irregular nuclear contours, condensed chromatin, small nucleoli and scant cytoplasm without granules.
| Occurs in older adults. Usually involves lymph nodes, bone marrow and spleen.
| Occurs in all ages, but most commonly in older adults. Often occurs outside lymph nodes. Aggressive.
| Occurs mainly in adult males. Usually involves lymph nodes, bone marrow, spleen and
GI tract. Associated with t(11;14) translocation overexpressing
cyclin D1. Moderately aggressive.
| Occurs in older adults. Usually involves lymph nodes, bone marrow and spleen. Most patients have peripheral blood involvement.
Indolent.
| Endemic in Africa, sporadic elsewhere. More common in immunocompromised and in children. Often visceral involvement. Highly aggressive.
| Localized or more generalized skin symptoms. Generally indolent. In a more aggressive variant,
[Sézary's disease, there is skin erythema and peripheral blood involvement.][
|-
! Peripheral T-cell lymphoma-Not-Otherwise-Specified
| Most common T cell lymphoma ][
| Variable. Usually a mix small to large lymphoid cells with irregular nuclear contours.][
| CD3][
|
| Probably consists of several rare tumor types. It is often disseminated and generally aggressive.][
|-
! Nodular sclerosis form of Hodgkin lymphoma
| Most common type of Hodgkin's lymphoma][
| Reed-Sternberg cell variants and inflammation. usually broad sclerotic bands that consists of collagen.][
| CD15, CD30][
|
| Most common in young adults. It often arises in the mediastinum or cervical lymph nodes.][
|-
! ''Mixed-cellularity subtype of Hodgkin lymphoma
| Second most common form of Hodgkin's lymphoma][
| Many classic Reed-Sternberg cells and inflammation][
| CD15, CD30][
|
| Most common in men. More likely to be diagnosed at advanced stages than the nodular sclerosis form. Epstein-Barr virus involved in 70% of cases.][
|}
]See also
BCP-1 cells
Ann Arbor staging
International Prognostic Index
Epstein barr virus
Lymphadenopathy
Chemotherapy regimens
References
External links
Timeline of discovery and treatment of Hodgkin's Lymphoma
US lymphoma statistics from the United States National Cancer Institute
Hodgkin Lymphoma and UK Non-Hodgkin Lymphoma statistics from the UK
Latest news and research on Lymphoma
Lymphoma Imaging Appearance - Chest Radiography
Category:Types of cancer
Category:Hematopathology
Category:Lymphoma
