[Usefulness of the modified Greipp's morphological classification of multiple myeloma cells]

In order to clarify the clinical usefulness of the morphological classification of multiple myeloma (MM) originally proposed by Greipp, et al. and modified by us, Giemsa-stained MM cells in bone marrows obtained from 61 untreated patients were analyzed. According to the original classification, there was no significant difference in survival time between the patients with plasmablastic MM and those with other types. However, the mean survival time of each type of MM according to the modified classification was 2014 days in mature MM, 1564 days in intermediate MM, 967 days in immature MM, and 254 days in plasmablastic MM. The survival time of plasmablastic MM was significantly shorter than those of other types. DNA aneuploidy was observed more frequently in plasmablastic MM than in other types. Furthermore, PCNA- and Ki-67-positive rates were higher in plasmablastic MM than in other ones. Four of five patients with plasmablastic MM who were treated with VAD(vincristine, doxorubicin, dexamethasone) regimen showed no significant effect, and most patients with the type died of sepsis or renal failure. From these results, it was concluded that patients with plasmablastic MM have a poor prognosis. Moreover, our modified classification is recommended as a clinically useful approach for selecting treatment strategy and predicting an accurate prognosis.