Only a few cases of IgE myeloma have been reported. Lymphadenopathy and hepatosplenomegaly are unusual. The WBC and platelet counts usually are normal. A low anion gap is sometimes present. The serum level of 2 -microglobulin is frequently elevated and correlates with myeloma cell mass.
Proteinuria is common because of excess synthesis and secretion of free monoclonal light chains.
Chemical paper strip tests of urine do not reliably detect Bence Jones protein, and the heat test is often misleading, but sulfosalicylic acid and toluene sulfonic acid are useful screening tests. However, in essentially all patients with light chain myeloma, a homogeneous M spike is demonstrable on protein electrophoresis of concentrated urine. Immunoelectrophoresis or immunofixation using monospecific antisera identifies the immunoglobulin class of the M spike in serum or urine. Osteoblastic lesions are rare, and thus radionuclide bone scans usually are not helpful. MRI may be useful, particularly in predicting outcome in patients with early-stage disease.