Waldenström macroglobulinaemia

Waldenström macroglobulinaemia is defined as a lymphoplasmacytic lymphoma with bone marrow involvement and a production of monoclonal IgM protein of any concentration. This bone marrow smear shows an infiltration by a characteristic neoplastic population, consisting of small mature lymphocytes with condensed nuclear chromatin, scanty cytoplasm and a high nuclear-cytoplasmic ratio (green arrow), plasmacytoid lymphocytes with eccentric locations of nuclei and pale cytoplasm (red arrow).