Chapter 1 - Peripheral Blood Smear Review

Summary

Despite all the advances in laboratory medicine, microscopic review of the peripheral blood smear is still highly informative and clinically relevant and remains an indispensable diagnostic tool. In a pediatric hospital, a common and challenging request is the evaluation of a newborn blood smear. This chapter provides an overview of some of the characteristics of a newborn smear and common reactive conditions.

Blood smear evaluation is often performed for three essential reasons: first, to clarify a flagged result such as immature cells or a low platelet count to rule out pseudo-thrombocytopenia from platelet clumping; second, to evaluate the morphology of red blood cells, white blood cells, and platelets; and, third, to confirm morphologic findings identified by lab staff or an instrument [1]. The latter may be requested by a physician due to a clinical suspicion or by members of the laboratory staff for review of an abnormal finding.