OBJECTIVETo investigate the clinicopathologic features of lymphoplasmacytic lymphoma (LPL) with Waldenström's macroglobulinemia (WM) and to evaluate the usefulness of immunophenotype analysis in diagnosis and differential diagnosis of the tumor.

METHODSA total of 40 cases of LPL with WM diagnosed according to the 2008 World Health Organization classification of tumors of hematopoietic and lymphoid tissues were analyzed using immunophenotype and follow-up information.

RESULTSThe mostly common initial clinical presentations were non-specific symptoms, such as fatigue, anemia and hemorrhage. Lymphadenopathy, splenomegaly and hepatomegaly were found in 42.5%, 20.0% and 12.5% of the patients respectively. The pattern of bone marrow involvement included mixed type (47.2%), diffuse type (41.7%) and interstitial type (11.1%). The nodal architecture was completely destroyed in one case and partially effaced with residual germinal centers and dilated sinuses in 8 cases. All of the neoplastic cells expressed CD20 and CD79a. Neoplastic plasma cells were positive for CD138 and CD79a. No cases expressed CD5. Four cases weakly expressed CD23. No significant prognosis related factors were identified in the survival analysis.

CONCLUSIONSLPL with WM is a rare indolent small B-cell lymphoma, which is commonly seen, in older male patients. The tumor frequently involves bone marrow and shows various clinical manifestations. Combination analyses of the bone marrow biopsy histology, immunophenotypic study and clinical data, especially the serum examination are important for the diagnosis of LPL with WM.