Coincidence of Gaucher's disease due to a 1226G/1448C mutation and of an immunoglobulin G lambda multiple myeloma with Bence-Jones proteinuria

We report about a 58-year-old female with coexisting type-I Gaucher's disea se (GD) and multiple myeloma (MM). The diagnosis of GD was made in early ch ildhood by means of bone marrow biopsy and was recently confirmed by analys is of the patient's genomic DNA for the underlying glucocerebrosidase mutat ions and the identification of the 1226G/1448C genotype. At the age of 24 y ears, the patient developed massive splenomegaly. Therefore, a splenectomy was performed. No further therapy was necessary for the next 34 years until 1999 when progressive anemia and thrombocytopenia occurred. Additional lab oratory analysis revealed high serum protein and immunoglobulin (Ig) G leve ls and evidence of monoclonal gammopathy and lambda light-chain proteinuria , indicating plasma cell dyscrasia. This diagnosis was confirmed by the det ection of osteolytic lesions in skeletal X-rays and a bone marrow biopsy sh owing an extensive infiltration with Gaucher cells and an increase of plasm a cells, which ex-pressed lambda light chains. When examined by means of el ectron microscopy, typical Gaucher cells, i.e., histiocytes containing tubu lar-structured cytoplasmatic material and spots of plasma cells with an inc rease of the endoplasmic reticulum, were found. GD associated with acquired Mh I has been described 13 times in the Literature from 1968 to 1997. Only three of the patients were suffering from IgG myeloma. This distribution o f the monoclonal component is in contrast to that of patients suffering fro m MM alone.