title: Lymphoepithelioid lymphoma (Lennert's lymphoma) is a monoclonal proliferation of helper/inducer T cells.
abstract: Lymphoepithelioid lymphoma (Lennert's lymphoma) was first described as a special variant of Hodgkin's disease. This lesion is characterized by a high percentage of epithelioid and T cells and rarely contains the classical Hodgkin's/Reed-Sternberg cells. Cytogenetic abnormalities indicate that Lennert's lymphoma is of T cell origin. In the present study, immunohistochemical investigation of four cases of Lennert's lymphoma revealed two major cell populations of T cells that predominantly express the helper-inducer phenotype and Ki-M6- and Ki-M8-positive macrophages and epithelioid cells. Double-staining experiments for the detection of cell surface antigens and the proliferation-associated antigen Ki67 showed that only the CD4-positive cells (helper-inducer T cells) were proliferating. Examination of the DNA of these Lennert's lymphoma samples also indicated that monoclonal rearrangement of the T cell receptor beta-chain genes has occurred, whereas the immunoglobulin heavy- and kappa-chain genes remained in germline configuration. Our results strongly suggest that Lennert's lymphoma is a CD4-positive T cell lymphoma.
mesh_terms: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis; D004273:DNA, Neoplasm / Q000235:genetics; D004848:Epithelium / Q000473:pathology; D005796:Genes; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008223:Lymphoma / Q000276:immunology / Q000473:pathology*; D011948:Receptors, Antigen, T-Cell / Q000032:analysis / Q000235:genetics; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D004273:DNA, Neoplasm; D011948:Receptors, Antigen, T-Cell