title: Immunohistochemical staining of non-Hodgkin's lymphoma in paraffin sections using the MB1 and MT1 monoclonal antibodies.
abstract: We have performed a single blind trial to assess the value of the monoclonal antibodies MB1 and MT1 in lymphoma classification. Sixty cases of non-Hodgkin's lymphoma (NHL) were stained with MB1 and MT1 using an indirect immunoperoxidase technique in paraffin sections. The majority of B tumours (27/33) stained with MB1, and most of the T tumours (24/27) stained with MT1. The MB1 antibody often produced rather weak staining but it was apparently highly specific for B cells, with only three (3/27) of the T tumours (two cases of 'malignant histiocytosis' of the intestine (MHI) and one pleomorphic T-cell lymphoma) displaying 'false' positivity. The MT1 antibody generally produced very strong staining, but it was not very selective, with 14/33 of the B lymphomas displaying 'false' positivity. the cross-reactivity observed in 17 cases led to only three misdiagnoses, two B tumours being designated as T lymphomas and one T tumour being designated as a B lymphoma. In a few cases (7/17), dual staining with both antibodies precluded firm diagnosis. In other cases (6/17), classification was possible despite some of the tumour cells showing dual staining. The seventeenth case was a plasmacytoma displaying MT1 positivity only. While the monoclonal antibodies MB1 and MT1 are of use in classifying lymphomas in paraffin section, they are not entirely lineage-specific, and the uncritical use of these two reagents alone may give rise to misdiagnosis; the use of a panel of monoclonal antibodies may yield more accurate results. As with any immunohistochemical marker, their limitations should be recognized; interpretation must be judicious and always in the context of the histological appearances.
authors.affiliation: Department of Pathology, University of Newcastle upon Tyne, U.K.
authors.forename: C M
authors.initials: CM
authors.lastname: Dobson
authors.forename: M W
authors.initials: MW
authors.lastname: Myskow
authors.forename: A S
authors.initials: AS
authors.lastname: Krajewski
authors.forename: F H
authors.initials: FH
authors.lastname: Carpenter
authors.forename: C H
authors.initials: CH
authors.lastname: Horne
mesh_terms: D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000276:immunology*; D003429:Cross Reactions; D006801:Humans; D007124:Immunoenzyme Techniques; D008228:Lymphoma, Non-Hodgkin / Q000145:classification*; D010232:Paraffin; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D010232:Paraffin