Polycythemia rubra vera and artifactual hypoglycemia.

A patient with polycythemia rubra vera had had a leukocyte count between 55,000 and 86,000/cu mm and had had serum glucose levels as low as 8 mg/dL. Despite these low serum glucose values, the patient was asymptomatic, and a more careful investigation disclosed that the hypoglycemia was artifactual. This phenomenon, reported in other leukemic states, to our knowledge, has not been previously described in patients with polycythemia rubra vera. Our case broadens the spectrum of the causes of artifactual low serum glucose concentration due to excessive glucose consumption by the WBCs. This phenomenon is related to extreme leukocytosis, regardless of the underlying disease. Unnecessary workup for hypoglycemia can be avoided if its artifactual nature is suspected in any patient with a reported low serum glucose level and high WBC count.