title: Diagnosis and outcome of 100 consecutive patients with extreme granulocytic leukocytosis.
abstract: OBJECTIVE
  To determine the clinical features, causes, and prognostic significance of extreme leukocytosis in adults.
  
  
  METHODS
  Medical records of 100 consecutive patients who presented at the Minneapolis Veterans Affairs Medical Center between March 1993 and January 1994 with more than 25,000 leukocytes/microL blood and with more than 50% granulocytes were reviewed. Demographic, clinical, and outcome information was recorded, and a cause of extreme leukocytosis was sought in each case.
  
  
  RESULTS
  Extreme leukocytosis was attributed to infection in 48 cases, advanced malignancy in 13 cases, hemorrhage in 9 cases, glucocorticoids in 8 cases, and other causes in 22 cases. Four patients had previously diagnosed conditions resulting in chronic leukocytosis. Higher leukocyte counts were associated with malignancy (chi2 for trend=12.5, P <0.002). Fever was more common in patients with infection (weighted rate ratio=3.7, 95% Confidence interval [CI]=2.2 to 6.2). Mortality was high overall (31%), and was greater in patients with noninfectious diagnoses compared with infected patients, an association which persisted after stratification by leukocyte count (weighted rate ratio=2.5, 95% CI=1.2 to 4.9).
  
  
  CONCLUSIONS
  Clinicians should be aware that extreme leukocytosis with a predominance of granulocytes is associated with infection in only 48% of cases. The presence of fever increases the likelihood that infection is the cause. Mortality is high, particularly in patients without infection.
authors.affiliation: Veterans Affairs Medical Center, Department of Medicine, University of Minnesota, Minneapolis 55417, USA.
authors.forename: M T
authors.initials: MT
authors.lastname: Reding
authors.forename: J R
authors.initials: JR
authors.lastname: Hibbs
authors.forename: V A
authors.initials: VA
authors.lastname: Morrison
authors.forename: W R
authors.initials: WR
authors.lastname: Swaim
authors.forename: G A
authors.initials: GA
authors.lastname: Filice
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006098:Granulocytes; D006801:Humans; D007958:Leukocyte Count; D007964:Leukocytosis / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology* / Q000401:mortality; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D016896:Treatment Outcome