Page 171 - Clinical Hematology Atlas

CHAPTER 15 ACUTE MYELOID LEUKEMIA 155

E
FIGURE 15–6E Positive a-naphthyl esterase (nonspecific) esterase stain in monocytes (left). Naphthyl
esterase stain inhibited by NaFl (right).

MORPHOLOGY
Peripheral Blood: Myeloblasts, promyelocytes, and other immature myeloid precursors
Monoblasts and promonocytes and monocytes—frequently more mature then those seen
in bone marrow
6 Auer rods (see Figure 15-2, B)
Bone Marrow: Monoblasts large with abundant, moderate basophilic cytoplasm; some with
folded nuclei, one or more prominent nucleoli
Promonocytes, irregular, convoluted nucleus, cytoplasm slightly basophilic; granules;
occasional vacuoles
6 Auer rods
Granulocytes and their precursor and monocytes and their precursors each comprise $20%

CYTOCHEMISTRY
Myeloperoxidase: positive (see Figure 15-2, E)
Specific Esterase: naphthol-AS-D chloroacetate esterase is positive in granulocytic cells and
weak in monocytic cells (see Figure 15-6, D)
Nonspecific Esterase:
• a-Naphthyl acetate esterase: positive in monocytic cells; inhibited by NaFl
(Figure 15-6, E)
• a-Naphthyl butyrate esterase: positive in monocytic cells (see Figure 15-8, D)

GENETICS
Recurrent genetic abnormalities: not defined
NOTE: inv(16) or t(16;16) and abnormal eosinophils are excluded from this category.
IMMUNOPHENOTYPE
CD13 , CD33 , CD14 CD4 , CD11b , CD64 , CD15 , CD36 1
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