lymphoma
[lim-fo´mah] any neoplastic disorder of lymphoid tissue, including
hodgkin's disease. Often used to denote
malignant lymphoma, classifications of which are based on predominant cell type and degree of differentiation; various categories may be subdivided into nodular and diffuse types depending on the predominant pattern of cell arrangement.
B-cell l's a heterogeneous group of lymphoid malignancies including most
non-Hodgkin's lymphomas, representing clonal expansions of malignant
B lymphocytes that have been arrested at a particular stage in their differentiation from primitive stem cells. B-cell lymphoma usually appears as a painless lymph node enlargement, although extranodal sites of origin are not uncommon. These lymphomas have been classified on the basis of morphologic features characteristic of the different stages of normal B lymphocyte differentiation.
lymphoma cu´tis primary skin involvement by a B-cell lymphoma without demonstrable systemic disease.
diffuse lymphoma malignant lymphoma in which the neoplastic cells infiltrate the entire lymph node without any organized pattern.
follicular lymphoma malignant lymphoma in which the lymphomatous cells are clustered into identifiable nodules within the lymph nodes that somewhat resemble the germinal centers of
lymphatic nodules. Follicular lymphomas usually occur in older persons and commonly involve many or all nodes as well as extranodal sites. Called also
nodular lymphoma.
follicular center cell lymphoma any of a large group of
B-cell lymphomas, comprising four subtypes classified on the basis of the predominant cell type (resembling small cleaved, large cleaved, small noncleaved, and large noncleaved follicular center
cells). Because of the wide variety of prognostic levels and the existence of tumors with several types of cells, the original four categories have now been divided up and scattered among several new categories of
follicular and
diffuse lymphomas.
histiocytic lymphoma a rare type of
non-Hodgkin's lymphoma of intermediate to high malignancy, characterized by large tumor cells that resemble
histiocytes morphologically but are considered to be of lymphoid origin. Many tumors formerly placed in this category are now considered to belong in one of the
large cell lymphoma groups.
large cell lymphoma any of several types of lymphoma characterized by formation of malignant large lymphocytes in a diffuse pattern; some varieties contain exclusively one type of cell, such as lymphoblasts or cleaved or uncleaved follicular center cells, and others have a mixture of cells, sometimes including ones that cannot be characterized as to lineage.
Lennert's lymphoma a type of
non-Hodgkin's lymphoma with a high content of epithelioid
histiocytes; bone marrow involvement is common and response to
chemotherapy is often poor.
lymphoblastic lymphoma a highly malignant type of
non-Hodgkin's lymphoma composed of a diffuse, relatively uniform proliferation of cells with round or convoluted nuclei and scanty cytoplasm, which are cytologically similar to the lymphoblasts seen in
acute lymphoblastic leukemia.
malignant lymphoma a group of malignant neoplasms characterized by the proliferation of cells native to the
lymphoid tissues, i.e.,
lymphocytes,
histiocytes, and their precursors and derivatives. The group is divided into two major categories:
hodgkin's disease and
non-Hodgkin's lymphoma.
mixed lymphocytic-histiocytic lymphoma non-Hodgkin's lymphoma characterized by a mixed population of cells, with the smaller cells resembling
lymphocytes and the larger ones
histiocytes, usually occurring in a nodular histologic pattern but sometimes evolving into a diffuse pattern.
non-Hodgkin's l's a heterogeneous group of
malignant lymphomas whose common feature is absence of the giant Reed-Sternberg
cells characteristic of
hodgkin's disease. They arise from the lymphoid components of the immune system, and present a clinical picture broadly similar to that of
Hodgkin's disease except that these diseases are initially more widespread, with the most common manifestation being painless enlargement of one or more peripheral lymph nodes. The nomenclature and classification of these lymphomas has been a subject of controversy. One widely accepted classification is based on two criteria: cytologic characteristics of the constituent cells and type of cell growth pattern (defined as either nodular [follicular] or diffuse). Another system of classification is based on the cell type of origin:
T- or
B-lymphocytes or
histiocytes. Still another formulation has been proposed, separating non-Hodgkin's lymphomas into major histopathologic subtypes using only morphologic criteria.
Diagnostic procedures used to confirm suspected non-Hodgkin's lymphoma include PET scans, gallium scans, and occasionally
lymphangiograms. If lymphoma is diagnosed, it will be staged using the same system as for
Hodgkin's disease.
Treatment will depend on the type and stage. It may be single agent or multiagent
chemotherapy,
radiation therapy,
biotherapy, or a combination. Blood transfusions and
bone marrow transplantation have shown efficacy for some types of lymphoma.
Patient care: major problems presented by the patient with non-Hodgkin's lymphoma include the management of side effects associated with treatment and the prevention of infection.
small lymphocytic lymphoma a diffuse form of
non-Hodgkin's lymphoma with a low grade of malignancy; it represents the neoplastic proliferation of well-differentiated
B lymphocytes and may present with either focal lymph node enlargement or generalized lymphadenopathy and splenomegaly. The predominant cell type is a compact, small, normal-appearing lymphocyte with a dark-staining round nucleus, scanty cytoplasm, and little size variation. It nearly always involves the bone marrow, and often malignant cells are found in the blood, so that its clinical picture is similar to that of
chronic lymphocytic leukemia. Called also
well-differentiated lymphocytic lymphoma.
T-cell l's a heterogeneous group of lymphoid tumors representing malignant transformation of the
T lymphocytes. Types include convoluted T-cell lymphomas, cutaneous T-cell lymphomas,
adult T-cell leukemia, and certain other conditions.
undifferentiated lymphoma malignant lymphoma composed of undifferentiated cells, i.e., cells that do not show morphologic evidence of maturation toward lymphocytes or histiocytes, which vary in size and may include bizarre giant forms.
lymphoma
/lym·pho·ma/ (lim-fo´mah) any neoplastic disorder of lymphoid tissue. Often used to denote malignant l., classifications of which are based on predominant cell type and degree of differentiation; various categories may be subdivided into nodular and diffuse types depending on the predominant pattern of cell arrangement.
adult T-cell lymphoma ,
adult T-cell leukemia/lymphoma see under
leukemia. B-cell lymphoma any in a large group of non-Hodgkin's lymphomas characterized by malignant transformation of the B lymphocytes.
B-cell monocytoid lymphoma a low-grade lymphoma in which cells resemble those of hairy cell leukemia.
Burkitt's lymphoma a form of small noncleaved-cell lymphoma, usually occurring in Africa, manifested usually as a large osteolytic lesion in the jaw or as an abdominal mass; Epstein-Barr virus has been implicated as a causative agent.
convoluted T-cell lymphoma lymphoblastic lymphoma with markedly convoluted nuclei.
cutaneous T-cell lymphoma a group of lymphomas exhibiting (1) clonal expansion of malignant T lymphocytes arrested at varying stages of differentiation of cells committed to the series of helper T cells, and (2) malignant infiltration of the skin, which may be the chief or only manifestation of disease.
diffuse lymphoma in an older classification method, malignant lymphoma in which the neoplastic cells diffusely infiltrate the entire lymph node, without any definite organized pattern.
follicular lymphoma any of several types of non-Hodgkin's lymphoma in which the lymphomatous cells are clustered into nodules or follicles.
follicular center cell lymphoma B-cell lymphoma classified by the similarity of the cell size and nuclear characteristics to those of normal follicular center cells; the four previous subtypes are scattered among several types of follicular and diffuse lymphomas.
histiocytic lymphoma a rare type of non-Hodgkin's lymphoma characterized by the presence of large tumor cells resembling histiocytes morphologically but considered to be of lymphoid origin.
Hodgkin's lymphoma see under
disease. intermediate lymphocytic lymphoma ,
lymphocytic lymphoma, intermediately differentiated mantle cell l. large cell lymphoma any of several types of lymphoma characterized by the formation of one or more types of malignant large lymphocytes, such as large cleaved or noncleaved follicular center cells, in a diffuse pattern.
large cell, immunoblastic lymphoma a highly malignant type of non-Hodgkin's lymphoma characterized by large lymphoblasts (B or T lymphoblasts or a mixture) resembling histiocytes and having a diffuse pattern of infiltration.
Lennert's lymphoma a type of non-Hodgkin's lymphoma with a high content of epithelioid histiocytes and frequently with bone marrow involvement.
lymphoblastic lymphoma a highly malignant type of non-Hodgkin's lymphoma composed of a diffuse, relatively uniform proliferation of cells with round or convoluted nuclei and scanty cytoplasm.
malignant lymphoma a group of malignancies characterized by the proliferation of cells native to the lymphoid tissues, i.e., lymphocytes, histiocytes, and their precursors and derivatives; the group is divided into two major clinicopathologic categories:
Hodgkin's disease and
non-Hodgkin's lymphoma. mantle cell lymphoma , mantle zone lymphoma a rare form of non-Hodgkin's lymphoma having a usually diffuse pattern with both small lymphocytes and small cleaved cells.
marginal zone lymphoma a group of related B-cell neoplasms that involve the lymphoid tissues in the marginal zone, the patchy area outside the follicular mantle zone.
mixed lymphocytic-histiocytic lymphoma non-Hodgkin's lymphoma characterized by a mixed population of cells, the smaller cells resembling lymphocytes and the larger ones histiocytes.
non-Hodgkin's lymphoma a heterogeneous group of malignant lymphomas, the only common feature being an absence of the giant Reed-Sternberg cells characteristic of Hodgkin's disease.
plasmacytoid lymphocytic lymphoma a rare variety of small lymphocytic lymphoma in which the predominant cell type is the plasma cell.
primary effusion lymphoma a
B-cell lymphoma associated with human herpesvirus 8 infection, characterized by the occurrence of lymphomatous effusions in body cavities without the presence of a solid tumor.
small B-cell lymphoma the usual type of small lymphocytic lymphoma, having predominantly B lymphocytes.
small cleaved cell lymphoma a group of non-Hodgkin's lymphomas characterized by the formation of malignant small cleaved follicular center cells, with either a follicular or diffuse pattern.
small lymphocytic lymphoma a diffuse form of non-Hodgkin's lymphoma representing the neoplastic proliferation of well-differentiated B lymphocytes, with focal lymph node enlargement or generalized lymphadenopathy and splenomegaly.
small lymphocytic T-cell lymphoma small lymphocytic lymphoma that has predominantly T lymphocytes.
small noncleaved cell lymphoma a highly malignant type of non-Hodgkin's lymphoma characterized by the formation of small noncleaved follicular center cells, usually in a diffuse pattern.
T-cell lymphomas a heterogeneous group of lymphoid neoplasms representing malignant transformation of the T lymphocytes.
U-cell lymphoma , undefined lymphoma a category of non-Hodgkin's lymphomas that cannot be classified into a definite type by either morphologic or known immunocytochemical markers.
lymphoma
(lim-fo'ma ) ('mat-a) plural.lymphomaslymphomata [ lymph- + -oma] A malignant neoplasm originating from lymphocytes. Common forms of lymphoma are listed in the subentries below. These include Hodgkin disease, mycosis fungoides, and non-Hodgkin lymphoma.
lymphomatous ('mat-us),
adjective See:
Hodgkin diseaseStaging
Staging of both Hodgkin and non-Hodgkin lymphoma is as follows: Stage I: involvement of a single lymph node or localized involvement. Stage II: Involvement of two or more lymph node regions on the same side of the diaphragm. Stage III: Involvement of several lymph node regions on both sides of the diaphragm. Stage IV: Involvement of extralymphatic tissue, such as the bone marrow.
anaplastic large cell lymphoma
Abbreviation: ALCL
A rare form of non-Hodgkin, T-cell lymphoma that may behave indolently when limited to the skin or may be more aggressive and spread to lymph nodes throughout the body.
body cavity lymphoma
Primary effusion lymphoma.Burkitt lymphoma
See: Burkitt lymphoma

CUTANEOUS T-CELL LYMPHOMA: Raised reddish-purple plaque on the skin of the hip
cutaneous T-cell lymphoma
Abbreviation: CTCL.
A malignant non-Hodgkin lymphoma with a predilection for infiltrating the skin. In its earliest stages, it often is mistaken for a mild, chronic dermatitis because it appears as itchy macules and patches, often on the chest or trunk. Later, the lesions may thicken, become nodular, or spread throughout the entire surface of the skin, the internal organs, or the bloodstream.
See: illustrationfollicular lymphoma
A B-cell, non-Hodgkin lymphoma found in adult and older patients. It results from a translocation of an oncogene from chromosome 14 to chromosome 18 [t(14; 18)]. Most instances of this lymphoma are indolent or slow growing.
hepatosplenic T-cell lymphoma
A rare, rapidly progressive lymphoma that develops in the liver, spleen, and bone marrow. It has been identified in patients taking immunosuppressive drugs for diseases such as inflammatory bowel disease.
Hodgkin lymphoma
See: Hodgkin, ThomasMediterranean lymphoma
Immunoproliferative small intestinal disease.

NON-HODGKIN LYMPHOMA: Bizarre-appearing lymphocytes revealing active mitosis (orig. mag. ×1000)
non-Hodgkin lymphoma
Abbreviation: NHL
Any of a group of malignant tumors of B or T lymphocytes. In 2008, the American Cancer Society estimated that about 66,100 Americans would be newly diagnosed with the disease. See:
illustration;
Hodgkin diseaseSymptoms
Painless lymphadenopathy in two thirds of patients is the most frequent presenting symptom. Others have fever, night sweats, and loss of 10% or more of body weight in the 6 months before presenting with symptoms of infiltration into nonlymphoid tissue. Additional involvement is in peripheral areas such as epitrochlear nodes, the tonsillar area, and bone marrow. NHL is 50% more frequent in occurrence in men than in women of similar age. In most cases the cause of NHL is unknown, but patients who have received immunosuppressive agents have an over 100 times greater chance of developing NHL, probably because the immunosuppressive agents activate tumor viruses.
Treatment
Specific therapy depends on the type, grade, and stage of the lymphoma. Combination chemotherapies, bone marrow transplantation, radiation therapy, and photochemotherapy may be given, depending on the specific diagnosis.
primary effusion lymphoma
A non-Hodgkin B-cell lymphoma that typically arises in body cavities such as the pleural, peritoneal, or pericardial spaces. It is caused by Kaposisarcoma herpesvirus (human herpes virus 8) and is usually found in patients with advanced immune suppression.
Synonym: body cavity lymphomalymphoma
any neoplastic disorder of lymphoid tissue. Often used to denote malignant lymphoma, classifications of which are based on predominant cell type and degree of differentiation; various categories may be subdivided into nodular and diffuse types, depending on the predominant pattern of cell arrangement. There is also a great deal of difference in the types of disease in the different animal species. There is a system of classification based on the histological characteristics of the lymphocytes.
African lymphomasee burkitt's lymphoma.
angiotropic large-cell lymphomaan uncommon form of the disease seen rarely in dogs; lesions most commonly in the lungs producing a syndrome similar in many ways to congestive heart failure.
bovine malignant lymphomathe tumor form of
bovine viral leukosis.
Burkitt's lymphomasee burkitt's lymphoma.
canine malignant lymphomathe commonest hemopoietic neoplasm of dogs. It is characterized by lymphoid tumors in multiple lymph nodes, spleen, liver or other organs. Lymphocytic leukemia with involvement of bone marrow is much less common.
cutaneous lymphomaround, raised cutaneous nodules or plaques caused by the infiltration of neoplastic lymphocytes with a tropism for epithelial cells. Occurs in cattle, dogs and humans. See also
mycosis fungoides.
follicular lymphomaa malignant lymphoma in which the lymphomatous cells are in clusters in the lymph node resembling follicles. Called also giant follicular lymphoma, nodular lymphoma.
giant follicular lymphomasee follicular lymphoma (above).
Hodgkin's type lymphomarare, but reported most frequently in the dog. A diagnosis depends on the identification of the Reed-Sternberg cell in a mixed population of lymphocytes accompanied by sclerosis.
immunoblastic lymphomamay be nonsecretory or may secrete immunoglobulins. See also
myeloma.
large cell lymphomaclassified as diffuse, large cells, large cell immunoblastic or mixed tumors with large cells.
lymphoblastic lymphomatumors of medium-sized lymphocytes or small noncleaved lymphocytes.
malignant lymphoma (histiocytic)a form in which the predominant cell is the prolymphocyte (reticulum cell).
malignant lymphoma (mixed cell)a form containing proliferations of both prolymphocytes and lymphocytes.
malignant lymphoma (poorly differentiated lymphocytic)a form in which the predominant cell is morphologically similar to the lymphoblast, containing a fine nuclear chromatin structure and one or more nucleoli.
malignant lymphoma (small cell lymphocytic, small cleaved cell, well-differentiated lymphocytic)the form in which the predominant cell is the mature lymphocyte.
malignant lymphoma (undifferentiated)a form in which relatively large stem cells with large nuclei, pale, scanty cytoplasm and indistinct borders predominate.
nodular lymphomasee follicular lymphoma (above).
T cell lymphomaa form in which the predominant cell is the mature lymphocyte.
thymic lymphomaoccurs most commonly in yearling cattle and cats. In cattle, it causes obstruction of the esophagus leading to ruminal tympany, engorgement of jugular veins and edema of brisket and submandibular space. In cats it is caused by feline leukemia virus infection and is usually associated with pleural effusion and accompanying dyspnea and regurgitation.