SUMMARY: Waldenström’s macroglobulinaemia (WM) is a low-grade B-cell lymphoproliferative disorder characterised by an immunoglobulin IgM monoclonal gammopathy and bone marrow infiltration by lymphoplasmacytic lymphoma. Clinical features may be related to the overall disease burden, such as anaemia, thrombocytopenia, and constitutional inflammatory symptoms, or may be directly attributable to the IgM paraprotein. The concentration of monoclonal IgM can vary widely in WM. There is no direct relationship between the concentration of monoclonal immunoglobulin IgM and bone marrow infiltration. The spectrum of monoclonal immunoglobulin IgM-related disorders is large because of the diversity of involved organs and pathogenic mechanisms. Lesions commonly result from the deposition of all or part of the M-IgM as aggregates, amorphous, crystalline, microtubular, or fibrillar forms. Other mechanisms include autoantibody activity against a tissue antigen, formation of immune complexes, and complement activation. In addition, even a small B-cell clone may absorb biologically active molecules or induce cytokine secretion. In our case report, we describe a female patient with monoclonal IgM and lambda liver deposition and we discuss the frequency and variety of disorders caused by deposition of monoclonal IgM and free light chain.