Pathoma - WBC Disorders - Acute Leukemia

Question 1

What is the basic premises behind acute leukemias?

Answer 1

They are a proliferation of BLASTS (cells cannot reach mature form)

Question 2

Definition of acute leukemia

Answer 2

Accumulation of >20% blasts in bone marrow

Question 3

What happens to mature cells in acute leukemia

Answer 3

Blasts “crowd out” normal hematopoiesis resulting in anemia (fatigue), thrombocytopenia (bleeding), neutropenia (infection)

Question 4

Describe the appearance of blasts on microscopy

Answer 4

Large, immature cells with punched out nucleoli

Question 5

How can acute leukemia be subdivided

Answer 5

Acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia (AML)

Question 6

What are the markers to differentiate AML and ALL

Answer 6

ALL = tdt

AML = MPO

Question 7

What are the associations of Down syndrome with acute leukemias?

Answer 7

ALL - after 5 y/o

AML (acute megakaryoblastic)- before 5 y/o

Question 8

What are the markers of B-ALL vs. T-ALL

Answer 8

B-ALL -> tdt, CD10, CD19, CD20

T-ALL –> tdt, CD2 to CD8

Question 9

Describe the treatment/prognosis of B-ALL

Answer 9

Excellent response to chemo but must provide prophylaxis to CSF and scrotum because chemo does not cross BBB or blood-testicular barrier

Question 10

Describe two cytogenic abnormalities involved in B-ALL

Answer 10

t(12;21) - good prognosis; children

t(9;22) - poor prognosis; adults (philadelphia)

Think for 12;21 –> ‘b’ can be flipped around to be a ‘d’ and ‘12’ can be flipped around to be ‘21’

Question 11

Common presentation of T-ALL

Answer 11

Thymic mass

Question 12

When are auer rods seen and what are they?

Answer 12

Seen in AML

Auer rods are crystal aggregates of MPO (which is a marker of AML)

Note the punched out nucleolus in image (= blasts)

Question 13

What is the translocation in Acute promyelocytic leukemia (APL)

Answer 13

t(15;17)

Question 14

What is the actual receptor that is translocated in APL

Answer 14

retinoic acid receptor (RAR)

Question 15

What is a complication of APL

Answer 15

DIC (Auer rods activate the coagulation cascade)

Question 16

Treatment of APL

Answer 16

All-trans-retinoice acid (ATRA)

Will bind the altered retinoic acid recepots and cause blasts to mature

Question 17

What is the presentation of acute monocytic leukemia

Answer 17

Infiltration of gums

Question 18

Which is more common in adults and children? AML vs ALL?

Answer 18

ALL - children

AML - adults (median age 65)

Question 19

Myelodysplastic sydrome (ineffective hematopoeisis of myeloid lineage) increases risk of what?

Answer 19

Acute myeloid leukemia (AML)