<prompt> Most common plasma cell tumor is -PlasmacytomaWaldenstorms macroglobinemiaMultiple myelomaPrimary amyloidosis  <response>: Multiple myeloma is a malignant proliferation of plasma cells. In multiple myeloma,plasma cells produce immunoglobulin of a single heavy light chain,a monoclonal protein commonly referred to as paraprotein.In some cases,only light chain is produced this appears in the urine as Bence Jones protein .Reference:Davidsons principles practice of medicine 22nd edition pg no 1046. 