title: [Persistent polyclonal B-cell lymphocytosis].
abstract: BACKGROUND
  Persistent polyclonal B-cell lymphocytosis (PPBL) is a benign condition associated with smoking.
  
  
  METHODS
  A 42-year-old woman was referred to an internist because of an abnormal blood test outcome identified during routine sampling. She had no symptoms; she had smoked for thirty pack years. Physical examination revealed no abnormalities. Laboratory analysis showed absolute lymphocytosis. A blood smear identified binuclear ('buttock') cells. The diagnosis of persistent polyclonal B-cell lymphocytosis (PPBL) was made, with nicotine abuse as the probable cause. The patient was advised to quit smoking.
  
  
  CONCLUSIONS
  Polyclonal B-cell lymphocytosis is a benign condition that is characterised by: (a) polyclonal increase of B-lymphocytes in peripheral blood; (b) the presence of binuclear lymphocytes (buttock cells) in microscopic differentiation; (c) polyclonal increase in IgM. Recognition is important for the prevention of unnecessary diagnostic testing.
authors.affiliation: Amphia Ziekenhuis, afd. Interne Geneeskunde, Breda, the Netherlands. nverheijden@amphia.nl
authors.forename: Nienke
authors.initials: N
authors.lastname: Verheijden
authors.forename: Tom A M
authors.initials: TA
authors.lastname: Ermens
authors.forename: Joost W J
authors.initials: JW
authors.lastname: van Esser
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000473:pathology*; D005260:Female; D006801:Humans; D008218:Lymphocytosis / Q000209:etiology* / Q000473:pathology*; D012907:Smoking / Q000009:adverse effects*; D016540:Smoking Cessation