ABSTRACT
Objective To explore the bone marrow pathology ,diagnosis and differential diagnosis of Waldenstrom macroglobulinemia(WM). Methods 19 WM patients was examined by bone marrow aspiration (BMA) and bone marrow biopsy (BMB) for morphology. Flow cytometry (FCM) and immunohistochemistry (IHC) for immunophenotyping. Results Plasmacytoid lymphocytes were identified in 11 BMA. All of 19 BMB were involved by lymphoma cells. 17 cases showed a predominance of small lymphocytes and 2 of plasmacytoid lymphocytes. Typically plasmacytoid lymphocytes were not seen in 4 cases. Patterns of bone marrow involvement were as follow: diffuse (12 cases), nodular (4 cases), interstitial (3 cases). Immunophenotypically, FCM showed all cases were CD_(19)~+, CD_(20)~+, CD_(22)~+, CD_5~- and CD_(10)~-. IHC revealed small lymphocytes and plasmacytoid lymphocytes were Pax5~+ CD_(20)~+ and plasma cells were CD_(38) CD_(138)~+ CD_(20)~- Pax5~-. Conclusion Small lymphocytes proliferation with plasmacytic differentiation is the typical bone marrow pathologic features of WM. IHC is benefit for identifying lymphocytes and plasma cells components. The Combination of morphology, FCM and IHC is contributive to the diagnosis and differentiation of WM.