Immunohistochemical characteristics of monocytoid B cell lymphoma, mantle zone lymphoma, small lymphocytic lymphoma (or B chronic lymphocytic leukemia), and hairy cell leukemia.

Biopsy specimens obtained from 2 patients with monocytoid B cell lymphoma, 7 with mantle zone lymphoma, 7 with small lymphocytic lymphoma or B chronic lymphocytic leukemia, and 6 with hairy cell leukemia were investigated using an immunohistochemical method to detect their immunophenotypic characteristics. Periodate-lysine-paraformaldehyde-fixed frozen biopsies from the lymph node, peripheral blood, bone marrow, spleen, tonsil, lung, and stomach were studied. Monocytoid B cell lymphoma exhibited the immunophenotype of surface(s) IgD-/DRC-1-/Leu-1(CD5)-/Leu-M5(CD11c)-, +/- on the neoplastic cells or neoplastic lesions, mantle zone lymphoma exhibited that of sIgD+/DRC-1++/Leu-1-,+/Leu-M5-, small lymphocytic lymphoma or B chronic lymphocytic leukemia that of Leu-1+/sIgD-,+sIgD-,+/DRC-1- > +Leu-M5-, and hairy cell leukemia that of Leu-M5++/sIgD- > +/Leu-1- > +/DRC-1-. We therefore suggest that these four types of lymphomas can be differentiated by a combination of anti-sIgD, DRC-1, Leu-1, and Leu-M5 monoclonal antibodies based on their immunophenotypic characteristics.