Chapuy, BjörnBjörnChapuyWulf, GeraldGeraldWulfTessen, H. W.H. W.TessenGriesinger, FrankFrankGriesingerTruemper, Lorenz H.Lorenz H.TruemperSchroers, RolandRolandSchroers2018-11-072018-11-072007https://resolver.sub.uni-goettingen.de/purl?gro-2/51862A 32 year old female smoker (20 pack years) presented with an asymptomatic lymphocytosis of 13,000/nl and splenomegaly. The patient's blood smear showed an absolute lymphocytosis with 65% atypical lymphocytes. A total of 1% of the lymphocytes were bilobulated. Bone marrow histology and immunphenotyping of blood and bone marrow excluded leukemia and non-Hodgkin's lymphoma. IgH-CDR-3 PCR analysis revealed a polyclonal pattern. In summary, a persistent polyclonal B-cell-lymphocytosis (PPBL) was diagnosed. The exact etiology of PPBL is still unclear, however, it is associated with a polyclonal raise in the lymphocyte count of CD27(+)IgD(+)-memory-B-lymphocytes due to a defect in apoptosis signaling and leukocyte homing to secondary lymphoid tissues. An association with cigarette smoking is obvious since all patients are smokers. From all published cases, only two developed a malignancy with an uncertain association with PPBL. We have been monitoring our patient for 6.5 years without any evidence of the development of a lymphoma.journal_article10.1007/s00108-007-1800-617287965000244677500010