[Persistent polyclonal B-cell lymphocytosis].

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.