EDTA‐induced pseudothrombocytosis and citrate‐induced platelet agglutination in a patient with Waldenstrom macroglobulinemia

Key Clinical Message Hematology analyzers sometimes generate spurious results. A patient had EDTA ‐induced pseudothrombocytosis and platelet agglutination in citrate blood samples. This case verifies that addition of 1% paraformaldehyde to the citrate tubes can prevent platelet clumping. Further, it illustrates the advantages of having access to more than one platelet count method.