ABSTRACT
W hite blood cells: Evaluation of the W BCs in the PB smear includes the percentages and absolute numbers of the different types and maturation stages ofW B C .
Segmented neutrophils (segs, polymorphonuclear cells or PMNs) are the pre dominant W BCs in normal PB. Variable lesser numbers of band form neutrophils (bands or stabs) may also be present and are an important reactive feature in pediat ric patients but of little consequence in adults. Table 1.3 depicts the morphological features of normal granulocyte maturation. “Left-shift” refers to the presence of immature granulocytes in the PB. Neutrophilia with a left-shift, including up to a few blasts, may be due to almost any condition that elicits a brisk inflammatory response. Granulocytosis with cells representing the full range of maturation and a prominence of mid-level maturation (myelocytic bulge) is observed in chronic myeloid leukemia (CM L). The presence of 5% or more blasts in the PB is rare with non-neoplastic conditions and should trigger a thorough investigation for clonal hematologic disease.
