Non-itchy/raised brown spots on back, spread to chest & stomach. biopsy shows overproduction of plasma cells; bone marrow biopsy normal. next steps?

characterize cells: What you report is not definitive. Is this a plasma cell-rich inflammatory process, or is it a multifocal plasma cell tumor? The pathologists can investigate the cells to determine if they are of mixed clonal origin (benign) or monoclonal (meaning all derived form a single parent, usually a sign of a cancer). This can be done by evaluating the surface light chain expression.