Persistent polyclonal B lymphocytosis with binucleated lymphocytes: a study of 25 cases

Persistent and polyclonal lymphocytosis of B lymphocytes (PPBL) with binucl eated lymphocytes is an entity characterized by a polyclonal lymphocytosis. The lymphocytosis is stable for years and binucleated lymphocytes are dete cted on peripheral blood smears. We previously described +i(3q) as a recurr ent chromosomal abnormality in seven PPBL patients. In this study we report a large series of 25 PPBL patients and demonstrated that PPBL was associat ed with +i(3q) in 77% of cases, premature chromosome condensation (PCC) in 50% and both abnormalities in 41% of cases. Furthermore, we demonstrated th at i(3q) was present in a minority of B cells, restricted to B lymphocytes independently of the kappa or lambda light Ig chain expression, and exclusi vely observed in non-binucleated cells. The benign clinical course of PPBL and the lack of biological evolution in the majority of cases suggest that recognition of these disorders is so imp ortant that aggressive therapy in PPBL has to be avoided. Whether this synd rome represents a premalignant or benign disease remains unclear. The persi stence of cytogenetic abnormalities after stopping tobacco use suggests no association with cigarette smoking.