Many conditions can cause a leukocytosis. The presence of certain findings may be an early warning sign for an underlying acute or chronic hematologic malignancy.
Patient selection: unexplained leukocytosis
B symptoms (associated with malignant lymphoma)
(1) unexplained loss of more than 10% of body weight in the 6 months before diagnosis
(2) unexplained fever with temperatures above 38°C
(3) drenching night sweats
(4) pruritis that is recurrent, generalized and otherwise unexplained and which ebbs and flows parallel to disease activity
Other symptoms:
(1) easy bruisability or bleeding tendency
(2) unexplained fatigue or weakness
(3) immunosuppression
Findings on physical exam:
(1) petechiae or bruises
(2) lymphadenopathy
(3) hepatosplenomegaly
(4) pallor
Laboratory findings:
(1) unexplained anemia
(2) thrombocytopenia or thrombocytosis
(3) immature/unidentified/atypical cells or blasts on peripheral blood smear
(4) persistent lymphocytosis, especially in an older adult
