Clinicopathological profile of Waldenström's macroglobulinemia: Experience from a tertiary care center

Abstract

Background: Waldenstrom macroglobulinemia (WM) is a rare mature B cell Neoplasm, characterized by monoclonal Immunoglobulin M (IgM) in the serum and lymphoplasmacytic infiltration in the bone marrow. It accounts for approx 2% of Non Hodgkin Lymphomas. The disease is slightly more common in elderly males, the median age at diagnosis being 63 years. The disease is very infrequent in India and only a few studies have been published on the disease. Hence, we bring out this study on Clinico-Pathological Profile of WM. Aims and Objectives: To study clinico-pathological profile of WM cases and to distinguish them from other plasma cell neoplasms as both the diseases have different treatment protocols and prognosis. Materials and Methods: A cross sectional observational study was conducted at tertiary care center over a period of two years. Six cases of WM were encountered and enrolled for the study due to their rarity and morphological overlap with plasma cell neoplasms. The WHO criteria were followed and patients fulfilling those criteria were included in the study. The diagnosis of WM was based on the morphologic and immunohistochemistry findings of biopsy specimens, the presence of a monoclonal IgM, and the presence of distinctive clinical characteristics. Results: Median age of patients was 60.5 years with a male preponderance. 33% of cases presented with B symptoms and 100% cases presented with moderate to severe anaemia. 50% of the cases had thrombocytopenia and hepatomegaly. All cases had albumin:globulin ratio reversal. Peripheral smear showed background staining, rouleaux formation, relative lymphocytosis. Plasmacytoid cells were present in two cases. Bone marrow aspirate smears showed features of lymphoplasmacytic infiltration with suppression of other lineages. BM biopsies were hypercellular and showed a diffuse pattern of marrow infiltration by lymphoplasmacytic cells. The immunostaining of the infiltrating lymphocytes were CD 20+ and plasma cells were CD138+. Serum protein electrophoresis and immunofixation electrophoresis confirmed IgM type of monoclonal gammopathy. Conclusion: WM is relatively a rare mature B cell neoplasm which at times can have morphological overlap with other plasma cell neoplasms. We conclude that correlation with clinical laboratory test results while making diagnostic decision is an integral part of recognition of WM due to low grade indolent course of the disease and better outcome.