Synchronous development of anaplastic large cell lymphoma (ALCL) and multiple myeloma (MM) in a patient is rare. To our knowledge, until now only one case has been reported. Here, we reported another one. This is a 63-year old woman who presented with a mass in upper abdominal skin. PET/CT showed the high metabolism in left abdominal skin and left axillary lymph nodes. Histopathologic and immunohistochemical evaluation identified the cutaneous mass as an ALK-negative ALCL. Bone marrow smear showed increased plasma cells which expressed CD38, CD138, and cLambda concomitantly. The increased monoclonal immunoglobulin IgD was detected by immunofixation electrophoresis.