ISOCHROMOSOME I(3Q) AND PREMATURE CHROMOSOME CONDENSATION ARE RECURRENT FINDINGS IN CHRONIC B-CELL LYMPHOCYTOSIS WITH BINUCLEATED LYMPHOCYTES

Chronic B cell lymphocytosis with binucleated lymphocytes (LWBL) is a recently described entity. The lymphocytosis is stable over years and atypical binucleated lymphocytes are detected on peripheral blood smea rs. Further investigation has shown a predominance in females, a polyc lonal increase in serum IgM and HLA-DR7 expression in most cases. In a lmost all cases cytogenetic studies with classical culture conditions have not shown any abnormality. We describe 7 patients with LWBL assoc iated with an abnormal karyotype. An additional i(3q) was found in 6 c ases. Premature chromosome condensation (PCC) was detected in all 7 ca ses. As both abnormalities are rarely present in other benign or malig nant proliferations, we suggest a strong correlation between LWBL and i(3q) and/or PCC.