Lymphomas

Lymphomas are malignant neoplasms of lymphoid cells and are divided into Hodgkin,s Disease and Non-Hodgkin's lymphomas. There are many categories of non-Hodgkin's lymphoma and the main types will be briefly described.

Lymphoblastic lymphoma is a high grade lymphoma, is composed of precursor T or B lymphoid cells, and can occur in all age groups but is more common in the young. The leukemic form is referred to as acute lymphocytic leukemia.

Small lymphocytic lymphoma is a low grade lymphoma, is composed of mature lymphocytes (nearly always B cells), and occurs in the elderly. The leukemic form is referred to as chronic lymphocytic leukemia.

Follicular lymphoma is a relatively common B-cell lymphoma composed of varying numbers of small-cleaved and large cells from follicle centers and occurs mainly in adults. A follicular lymphoma composed mainly of small cleaved cells is a low grade lymphoma and the leukemic form has been referred to as lymphosarcoma. Follicular lymphoma composed mainly of large cells is of intermediate grade. Follicular lymphoma of mixed cell types also occurs.

Mantle cell lymphoma is an aggressive lymphoma of small B-cells derived from the follicle mantle. It occurs in older adults.

Diffuse large B-cell lymphoma is an intermediate grade lymphoma which occurs in all age groups and more frequently in older adults.

Burkitt's lymphoma is a high grade B-cell lymphoma occurring more frequently in the young. Cases presenting as acute leukemia are referred to as ALL-L3. Burkitt's lymphoma can occur in adults and may be associated with immunodeficiency.

Peripheral T-cell lymphomas occur more frequently in adults and are much less common than B cell lymphomas in the United States. The clinical course is generally aggressive.

Anaplastic large cell lymphoma is a rare tumor occurring in children and adults groups. T, B, and null cell types have been identified. The clinical course is similar to that of large cell lymphoma.

Marginal zone B-cell lymphoma is composed of small cells and monocytoid cells (with more abundant cytoplasm) and is a low grade lymphoma. This lymphoma may originate in extranodal mucosa-associated lymphoid tissue (MALT) or in lymph nodes.

Hodgkin's disease of lymphoma is divided into classic forms characterized by presence of classic Reed-Sternberg cells and lymphocyte predominant type characterized by absence of classic Reed Sternberg cell and presence of atypical B cells with polylobated nuclei.

University of Wisconsin Cytogenetic Services