Page 1044 - Hematology_ Basic Principles and Practice ( PDFDrive )

Chapter 59 Clinical Manifestations and Treatment of Acute Myeloid Leukemia 927

MPO MPO ANAE COES

A B C D
Fig. 59.3 CYTOCHEMISTRY: MYELOPEROXIDASE, α-NAPHTHYL ACETATE ESTERASE, AND
COMBINED ESTERASE REACTIONS. The MPO reaction is easily performed, can be done in less than a
few minutes, and provides important initial information about the lineage of the blasts, particularly in cases
in which morphologic assessment is difficult. In many laboratories it is routinely performed for all new acute
leukemias. The MPO reaction should be interpreted in the blast population and expressed as a percentage of
blasts that are positive. (A) The positive MPO reaction is strong. (B) The reaction is weak and seen in only
some blasts. A counterstain would have obscured the weak reaction product. A weak MPO reaction is not
uncommon in cases of acute myeloid leukemia (AML) associated with myelodysplasia (as in [B]). The neu-
trophils in such cases are also only weakly positive (bottom cell [B]). The ANAE reaction is a nonspecific esterase
reaction positive in most monocytic cells ([C] orange-brown cell on left compared to negative neutrophil, and
erythroid cell, middle and right). The ANAE reaction is interpreted as positive in cells as a percentage of
nonerythroid elements. A significant monocytic component is usually defined as 20% or greater of the non-
erythroid elements and is usually required for making a diagnosis of acute myelomonocytic leukemia. It is
notable that in some cases of AML with inv(16) (i.e., AML with abnormal eosinophils), the monocytes are
ANAE negative. A COES reaction uses another nonspecific esterase reaction for monocytes, α-naphthyl
butyrate esterase, together with the specific esterase, chloroacetate esterase, for granulocytes. The combination
allows simultaneous evaluation of granulocytes (blue reaction product) and monocytes (orange-brown reaction
product). (D) Acute myelomonocytic leukemia. A monocyte (top), a granulocyte (right), and a myelomonocytic
hybrid cell that exhibits both the orange-brown and blue reaction products (bottom). ANAE, α-Naphthyl
acetate esterase; COES, combined esterase; MPO, myeloperoxidase.

TABLE WHO Classification of Acute Myeloid Leukemia (2008)
59.1
Category Subtype/Definition Category Subtype/Definition
AML with recurrent t(8;21)(q22;q22); RUNX1-RUNX1T1 a Myeloid sarcoma
cytogenetic inv(16)(p13.1q22); CBFB-MYH11 a Myeloid Transient abnormal myelopoiesis
abnormalities t(16;16)(p13.1q22); CBFB-MYH11 a proliferations Myeloid leukemia associated with Down syndrome
t(15;17)(q22;q12); PML-RARA a related to Down
t(9;11)(p22;q23); MLLT3-MLL syndrome
t(6;9)(p23;q34); DEK-NUP214
inv(3)(q21q26.2); RPN1-EVI1 Blastic plasmacytoid
t(3;3)(q21;q26.2); RPN1-EVI1 dendritic cell
t(1;22)(p13q13); RBM15-MKL1 neoplasm
AML with Morphologic features of MDS, or Acute leukemia of Acute undifferentiated leukemia
MDS-related Prior history of MDS or MDS/MPN, or ambiguous Mixed phenotype acute leukemia with
changes MDS-related karyotype, and lineage t(9;22)((q34;q11.2); BCR-ABL1
None of the recurrent genetic abnormalities above t(v;11q23); MLL rearranged
Mixed phenotype acute leukemia, B/myeloid, NOS
Therapy-related Late complications of cytotoxic chemotherapy Mixed phenotype acute leukemia, T/myeloid, NOS
myeloid (alkylating agents, topoisomerase II inhibitors)
neoplasms and/or ionizing radiation therapy b Provisional entities AML with mutated NPM1
AML with mutated CEBPA
AML, not otherwise AML with minimal differentiation NK-cell lymphoblastic leukemia/lymphoma
specified AML without maturation
AML with maturation
Acute myelomonocytic leukemia
Acute monoblastic/monocytic leukemia
Acute erythroid leukemia
Acute megakaryoblastic leukemia
Acute basophilic leukemia
Acute panmyelosis with myelofibrosis
a Diagnosis of AML regardless of percent blasts
b Excluded are patients with AML who have transformed from MPN
AML, Acute myeloid leukemia; MDS, myelodysplastic syndrome; MPN, myeloproliferative neoplasm; NK, natural killer cell; NOS, not otherwise specified.