Cytogenetic analysis of de novo CD5-positive diffuse large B-cell lymphoma.

Aims:  De novo CD5-positive diffuse large B cell lymphoma (CD5+DLBL) is a subtype of DLBL with poor clinical outcome. To investigate the cytogenetic pathogenesis of CD5+DLBL, we analyzed the chromosomal findings of 18 patients with CD5+DLBL. Methods:  Tumor cells were cultured and metaphase was captured by colchicine exposure. Using trypsin-Giemsa banding, the chromosomes were analyzed according to the International System for Human Cytogenetic Nomenclature. Results:  Metaphase was acquired from 12 patients. Normal karyotypes were seen in two patients and abnormal karyotypes in the remaining 10. The numbers of chromosomes ranged from 45 to 90. Gain, loss and rearrangements of various chromosomes were seen. Frequent breakpoints were located at chromosome 1 band p13, 3q27, 6q13, 7q32, 14q32, 18q21 and 19q13. There was no diagnosis-specific abnormality. A relationship between chromosomal findings and clinical outcomes such as involved site, relapse or survival, was not observed. Conclusion:  Since previous and the present studies on the chromosomal analysis of CD5+DLBL are also contradictory, more detailed comprehensive genetic analysis appears to be needed to elucidate the biological mechanisms of CD5+DLBL.