AML

Question 1

Acute Myeloid Leukemia

Answer 1

Immature myeloid cells accumulate in the bone marrow and peripheral blood
Average age is 67, second most common pediatric leukemia

Question 2

AML Risk Factors

Answer 2

Benzene exposure
Down's syndrome
Fanconi's anemia
MDS
Obesity 
Radiation

Question 3

M0

Answer 3

AML with minimal differentiation
<3% staining positivity with SBB or MPO
>20% myeloid blasts

Question 4

M1

Answer 4

AML without maturation
>3% positivity with MPO and SBB
Significant number of myeloblasts
Can see Auer rods

Question 5

M2

Answer 5

AML with maturation
>20% myeloblasts
>10% mature granulocytes
t(8;21) translocation gives better prognosis

Question 6

M3

Answer 6

Acute promyelocytic leukemia (APL)
Bleeding and DIC
>20% myeloblasts and abnormal promyelocytes 
Low WBC count
t(15;17) makes ATRA therapy effective

Question 7

M3v

Answer 7

Hypogranular form

Question 8

M4

Answer 8

Acute myelomonocytic leukemia (AMML)
Splenomegaly, gingival bleeding, bacterial infections, CNS changes, skin lesions
Most common AML
Positive for MPO, SBB, and combined esterase

Question 9

M4eo

Answer 9

Increased abnormal eosinophils in bone marrow
Pseudo-Pelger Huet syndrome
Abnormal eosinophils are positive for PAS
t(16;16)

Question 10

M5

Answer 10

Acute monocytic leukemia
M5a: lots of monoblasts
M5b: lots of promonocytes

Question 11

M6

Answer 11

Acute erythroblastic leukemia

Question 12

M6a

Answer 12

Erythroleukemia with myeloid involvement
Bone marrow has >50% erythroid precursors and >20% myeloblasts
PAS and MPO positive
Megaloblastoid changes

Question 13

M6b

Answer 13

Pure erythroid leukemia

>80% erythroid cells in the bone marrow

Question 14

M7

Answer 14

Acute Megakaryocytic Leukemia
Cytochemical stains are inconclusive
Dry tap
See micromegakaryocytes 
Associated with Down syndrome and myelodysplasia