[A case of light chain deposition disease involving kidney and bone marrow with microangiopathic hemolytic anemia].

We report a case of light chain deposition disease in a 59-yr-old female showing deposition of monoclonal light chain in the kidney and bone marrow accompanied with a schistocytosis, the morphologic finding of microangiopathic hemolytic anemia. The immunofluorescence examination of the kidney revealed strongly stained kappa-light chain deposits on the glomerular mesangium and capillary wall, tubules, and vessel wall. The electron microscopy demonstrated electron-dense deposits on the glomerular basement membrane and mesangium. Anemia was observed with schistocytosis and Howell-Jolly body in the peripheral blood smears. The immunohistochemical examination of the bone marrow showed the presence of kappa-light chain deposits in scattered plasma cells and thickened vessel wall in the absence of a prominent plasma cell proliferation. Although an immunofixation electrophoresis failed to detect a monoclonal gammopathy, the presence of monoclonal protein could be identified by an abnormal kappa/lambda ratio on the serum free light chain analysis.