We report a 27-year-old man who presented with fatigue, moderate weight loss and progressive abdominal distension as primary manifestations of a light-chain multiple myeloma (MM). Liver scan showed an enlarged liver with multiple low attenuation areas. Liver biopsy revealed sinusoidal infiltration by small size cells identified as Kappa light chain-producing primitive plasma cells by immunohistochemistry. The patient responded to three courses of EDAP. Subsequently he received intensive therapy with busulfan/melfalan and a peripheral blood stem cell transplantation enriched for CD34+ cells from his HLA-identical brother. No acute graft-versus-host disease was detected. Now, 12 months after transplant, the patient is asymptomatic.