[Morphologic features of the binucleated lymphocytes for the assesment of persistent B-cell polyclonal lymphocytosis].

Observation of binucleated lymphocytes on a blood film is a cornerstone event to assess persistent polyclonal B-cell lymphocytosis diagnosis (PPBL). But seldom case reports mentioned their finding in other contexts, mainly B-cell lymphoproliferative neoplasms such chronic lymphocytic leukemia or in reactive circumstances as multiple sclerosis undergoing natalizumab treatment. We aimed to check if some particular morphologic features were more specificaly linked to PPBL, reviewing blood films of series of patients affected by PPBL or harbouring binucleated lymphocytes whatever the diagnosis was.

Morphologic features of binucleated lymphocytes to assess the diagnosis of persistent B-cell polyclonal lymphocytosis or other mature B-cell neoplasms.

The observation of binucleated lymphocytes (BNLs) on a peripheral blood smear is essential to the diagnosis of persistent polyclonal B-cell lymphocytosis (PPBL). Only a few case reports have mentioned their presence in other contexts, mainly mature B-cell neoplasms such as chronic lymphocytic leukemia or reactive circumstances such as multiple sclerosis undergoing natalizumab treatment. We sought to investigate whether any particular morphologic features of BNL were more specific to PPBL than other diseases.