Correlations between karyotype and cytologic findings in multiple myeloma.

Abstract

In multiple myeloma, correlations between cytogenetic and morphologic findings are hampered by the relatively scarce chromosomal data and the lack of a widely accepted morphologic classification. The aim of the analysis, comprising 111 patients with multiple myeloma, was to study possible correlations between karyotype and a morphologic classification proposed by Bartl et al. Grade of plasma cell infiltration, predominant cell types (Marschalko, small, cleaved, polymorphous, asynchronous, blastic) and grade of malignancy are the basis of this classification. A pathologic karyotype was found in the bone marrow of 39/111 patients (35%). The incidence of chromosomal anomalies closely correlated with the grade of infiltration, plasma cell type and grade of malignancy. Chromosomal anomalies were rarely detected in patients with low infiltration (16%), but they were frequently found in high-grade infiltration (69%). A low incidence was found in Marschalko (25%) or small cell type (15%); the incidence was much higher in cleaved (75%), asynchronous (65%) and basic cell types (71%). An abnormal karyotype was more frequently found in high (71%) than in intermediate (53%) or low (23%)-grade malignant multiple myeloma. The most consistent structural chromosomal aberration found in five patients was translocation t(11;14)(q13;q32). In four of the five patients small, often cleaved plasma cells were the predominant cell types. These reported correlations between morphological and cytogenetic findings must be confirmed by future studies.