title: T-cell-rich B-cell lymphoma.
abstract: Five cases of B-cell lymphoma are described in which the morphology and initial immunohistochemistry suggested a diagnosis of T-cell neoplasia. In four cases, the histological picture was that of an adult pleomorphic T-cell lymphoma; the fifth case was a lymphocytic lymphoma (CLL) with an accompanying T-cell lymphocytosis in the peripheral blood. Immunohistochemistry on both frozen and paraffin-embedded material showed that the cellular population in all five cases consisted mainly of T-cells; less than 10% of the cells stained as B-cells. However, immunoglobulin immunostaining combined with use of the new lineage-related monoclonal antibodies reactive in paraffin section revealed that the B-cells constituted the neoplastic population. Genetic analysis showed no evidence of clonality in the T-cells, nor was it able to detect rearrangement in the small number of clonal B-cells present. These cases represent a variety of B-cell neoplasia that mimicks T-cell lymphoma morphologically and immunologically. The vigorous T-cell reaction seen in such lymphomas means that the malignant population can be correctly identified only by careful examination of the immunohistochemical findings.
authors.affiliation: Department of Histopathology, University College, London, England.
authors.forename: A D
authors.initials: AD
authors.lastname: Ramsay
authors.forename: W J
authors.initials: WJ
authors.lastname: Smith
authors.forename: P G
authors.initials: PG
authors.lastname: Isaacson
mesh_terms: D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000473:pathology*; D001706:Biopsy; D003937:Diagnosis, Differential; D005629:Frozen Sections; D006801:Humans; D007124:Immunoenzyme Techniques; D008198:Lymph Nodes / Q000473:pathology*; D008223:Lymphoma / Q000378:metabolism / Q000473:pathology*; D013601:T-Lymphocytes / Q000473:pathology*
chemical_list: D000911:Antibodies, Monoclonal