Immunoglobulin G Kappa Lymphoplasmacytic Lymphoma with Associated Al Amyloidosis: A Rare Combination!

Lymphoplasmacytic lymphoma (LPL) is a low-grade B-cell neoplasm, composed of small B-lymphocytes, plasmacytoid lymphocytes, and plasma cells involving bone marrow and sometimes lymph nodes or spleen and forms 1% of all non-Hodgkin lymphomas. LPL with bone marrow involvement and an Immunoglobulin M (IgM) monoclonal gammopathy of any concentration is designated as Waldenstrom macroglobulinemia (WM). Due to their frequent co-occurrence, the terms LPL and WM are often used interchangeably in clinical practice. However, although the clinical diagnosis of WM is restricted to cases with an IgM monoclonal protein, the World Health Organization recognizes that LPL can rarely present with paraproteins of immunoglobulin G (IgG) or immunoglobulin A (IgA). LPL associated with non IgM gammopathies are extremely rare and form > 5% of all LPLs. We hereby present the case of a 65-year-old female with no previous co morbidities who presented with nonspecific complaints of weight loss, easy fatigability, and night sweats. Examination was within the normal limits except for the presence of subcentimetric axillary lymphadenopathy. She was found to have anemia with an altered A/G ratio M spike of 2.10 g/which was IgG kappa on immunofixation electrophoresis. The bone marrow revealed a mixture of lymphocytes, lymphoplasmacytoid cells, and plasma cells along with the presence of amyloid deposits. MYD88 L265P mutation done on peripheral blood was positive, and based on these, she was diagnosed with a case of IgG Kappa LPL with associated amyloidosis.