Smoking-induced monoclonal B-lymphocytosis in two female smokers: what are the odds?

Persistentpolyclonal B-cell lympho-cytosis (PPBL) is awell-known entity, characterized by a persistent lymphocytosis with circulating atypical lymphocytes. Affecting mainly younger females, this condition has been linked with chronic tobacco use. Reports have shown atypical lymphocytes in smoking-related B-lymphocytosis to display some genetic and molecular features normally seen only in hematologic malignancies. In addition, a large study has associated chronic lymphocytic leukemia (CLL) with chronic smoking. We describe herein two unique patients with chronic smoking history, persistent neutrophilia and incidentally discovered monoclonal B-lymphocytosis (MBL). The MBL inthe firstpatient was preceded by a PPBL. Clinical scenarios in our patients suggest that the MBL might have been caused by chronic cigarette smoking. We further postulate that tobacco-induced B-lymphocytic proliferation may become neoplastic.