Flow Cytometric, Morphologic, and Laboratory Comparative Study in Patients With Leukocytosis and Cytopenia

We wanted to evaluate the effectiveness of flow cytometry immunophenotyping (FCI) as a screening test for patients with leukocytosis and cytopenia.

We identified 320 patients during August 2016 to December 2016 and evaluated FCI and morphology of peripheral blood smears (PBSs).

The most common indications for FCI included history of hematologic malignancy (HHM, n = 126), leukocytosis (n = 80), and cytopenia (n = 53). Positive FCI rate was low with a range of 4.4% to 12.5% in patients with absolute neutrophilia regardless of HHM, if cases with circulating blasts were excluded. Patients with absolute lymphocytosis had a 93% positive FCI rate. Patients with HHM and pancytopenia showed a higher incidence of positive FCI findings than patients without HHM and with isolated cytopenia. PBS morphology correlated strongly with FCI (P = .0001).

PBS evaluation is an accurate and cost-effective screening test. FCI for patients with mature neutrophilia and isolated cytopenia has a very low yield.