B-CELL LYMPHOMA ACCOMPANYING MONOCLONAL MACROGLOBULINEMIA WITH FEATURES SUGGESTING MARGINAL ZONE B-CELL LYMPHOMA

Waldenstroem's macroglobulinemia is usually closely related to a histo pathologic subtype called lymphoplasmacytoid lymphoma in the Revised E uropean-American Lymphoma (REAL) classification. Here, we report a cas e of B-cell lymphoma accompanied by monoclonal macroglobulinemia and p athologically compatible with marginal zone B-cell lymphoma (MZBCL) ra ther than lymphoplasmacytoid lymphoma. The patient was a 74-year-old m an with lymphomatous lesions that were recognized as submandibular lym phadenopathy, subcutaneous tumor and bilateral orbital masses, but wit h no bone marrow involvement. The atypical lymphoid cells that occupie d the lymph node were varied such as small cells harboring irregular n uclei, monocytoid B-cells, large cells with vesicular nuclei, and plas ma cells. The tumor cells expressed CD19, CD20, IgM and kappa on their cell surfaces and cytoplasmic IgM, but not CD5 or CD10. These finding s suggest that the clinical and histopathologic findings of this case are compatible with those of MZBCL rather than lymphoplasmacytoid lymp homa. Serum IgM was elevated up to 4080 mg/dl and M-proteinemia of IgM -kappa type was confirmed by immunoelectrophoresis. Hyperviscosity syn drome caused by monoclonal IgM was not apparent. Immunohistochemical s tudy confirmed that monoclonal IgM-kappa was produced and secreted fro m the tumor cells of MZBCL. This case suggests a close relationship be tween MZBCL and lymphoplasmacytoid lymphoma, from the perspective of t he cellular origin during B-cell differentiation. (C) 1997 Elsevier Sc ience Ireland Ltd.