Prediction of prognosis by electron microscopic analysis of myeloma cells

Myeloma cells were ultrastructurally analyzed in relation to survival in 54 patients with myeloma who were treated with melphalan-prednisolone or cyclophosphamide-prednisolone. Since previous studies by electron microscope had demonstrated that the degree of nuclear-cytoplasmic asynchrony of myeloma cells was associated with poor prognosis, this study focused on three kinds of nuclear abnormalities and eight kinds of cytoplasmic abnormalities. The patients were classified into three groups according to the presence of these abnormalities. The median survival times of the first group with five or fewer of 11 different kinds of abnormalities, the second group with 6-8 abnormalities and the third group with nine or more abnormalities were 2353, 531, and 115 days, respectively. Further more, this classification by ultrastructural abnormalities corresponded to those by the initial hemoglobin concentrations, platelet counts, and percentages of myeloma cells and plasmablasts in the bone marrow. These findings suggest that ultrastructural analysis of nuclear and cytoplasmic abnormalities, in addition to nuclear maturity, of myeloma cells may provide important information for predicting the prognosis in myeloma patients.