Abstract
Multiple myeloma is recognized as a neoplasm of phenotypically mature plasma cells which produces a variety of clinical symptoms related both to tumour infiltration of the bone marrow and cytokine production. The latter results in bone disease and a complex interactive network between plasma cells, marrow stromal cells and other hematopoietic cells. This serves to sustain the myeloma proliferative pool and promote maturation and secretion of monoclonal immunoglobulin. Whereas the recognizable tumour cells in myeloma are the most mature B cells, early lymphoid cells are involved in the disease and probably represent the proliferative preβplasma cell compartment. The definition of the myelomaβstem cellβ remains controversial, but our understanding of early preβplasma cell differentiation in multiple myeloma has been aided by studies on normal nonβneoplastic equivalents. Techniques like high resolution flow cytometry, flow cytometric DNA analysis and improvements in our ability to obtain karyotypic data in multiple myeloma will improve our understanding of myeloma cell biology, hopefully yielding new prognostic information. Finally, improvements in assessing prognosis will help identify patients whose survival with standard therapy is limited and how may require innovative or aggressive treatment protocols. These individuals must be separated from patients who either require no initial therapy or who are likely to have good outcomes with standard approaches.