diffuse lymphoma

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.

centrocytic lymphoma  mantle cell l.

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.

giant follicular lymphoma  follicular l.

granulomatous lymphoma  Hodgkin's disease.

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.

nodular lymphoma  follicular l.

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.

undifferentiated lymphoma  small noncleaved cell l.

---

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.

adult T-cell lymphoma (adult T-cell leukemia/lymphoma) adult T-cell leukemia/lymphoma.

African lymphoma Burkitt's lymphoma.

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.

Burkitt's lymphoma see burkitt's lymphoma.

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.

giant follicular lymphoma follicular lymphoma.

granulomatous lymphoma Hodgkin's disease.

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.

Hodgkin's lymphoma Hodgkin's disease.

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.

nodular lymphoma follicular lymphoma.

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.

well-differentiated lymphocytic lymphoma small lymphocytic lymphoma.

---

diffuse lymphoma

A lymphoma composed of sheets of cells without germinal centers, which often spill into adjacent adipose and other tissues; DLs are often more aggressive than follicular lymphomas. See Lymphoma.