Acute Leukemias Flashcards Preview

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Flashcards in Acute Leukemias Deck (33):
1

What is the difference between an acute neoplasm and a chronic neoplasm?

Acute - presence of immature cells (Blasts)

Chronic- presence of differentiated (mature) cells

Both may be of either Lymphoid or Myeloid origin

2

What is leukemia?

Malignant neoplasm characterized by the replacement of the bone marrow by neoplastic cells

3

What is a lymphoma?

Proliferations of hematopoietic neoplasms arising as discrete tissue masses

4

In general, what are some clinical features of acute leukemias?

Abrupt stormy onset
Suppression of normal hematopoiesis
Anemia - fatigue
Neutropenia - fever
Thrombocytopenia - bleeding

5

What are some symptoms that are more likely to occur in ALL than AML?

ALL more likely to have generalized lymphadenopathy, splenomegaly, hepatomegaly, CNS involvement

6

What acute leukemia are kids more likely to acquire?

ALL (80%)

7

What are the neoplastic cells in ALL?

Lymphoblasts (B or T lymphoblasts)

85% of ALLs are pre-B cell neoplasms

8

What are the special clinical features of T-ALL?

Commonly presents in adolescent males with thymic involvement

Presents as a mediastinal mass

9

How is the diagnosis of ALL made?

Microscopic analysis -
See lymphoblasts with scant basophilic cytoplasm and fine nuclear chromatin

Flow cytometry for T and B cell markers

TdT test

10

What is the specific stain used to diagnose ALL?

TdT
Terminal deoxynucleotidyl transferase
Positive in over 95% of ALLs

11

What are some common chromosomal abnormalities with ALL?

Hyperdiploidy (over 50 chromosomes)

t(12;21) TEL-AML

t(9;22) - BCR-ABL; Philadelphia chromosome

t(4;11) (MLL gene)

12

What is the general prognosis for ALL?

Complete remission rates of 90% or better in children

Cure in up to 2/3 patients

13

What are some favorable prognostic indicators of ALL?

Age 2-10
Hyperdiploidy
TEL-AML t(12;21) mutation

14

What are some unfavorable prognostic indicators of ALL?

Diagnosis before 2
Adolescent or adult presentation
Presence of t(9;22) (Philadelphia chromosome)

15

Which leukemia are adults more likely to acquire?

AML (80%)

16

AML is a highly heterogeneous disease. What cell types may AML involve?

Erythroblasts
Monoblasts
Megakaryoblasts
Myeloblasts

17

What are some general causes of AML (the four main categories of WHO classification)?

1. AML with recurrent genetic abnormalities
2. AML arising from myelodysplastic syndrome
3. Therapy related
4. Not otherwise specified

18

What are the two most important mutations associated with AML?

t(15;17) PML/RAR-alpha

t(11q23;v) MLL

19

What is myelodysplastic syndrome (MDS)?

Pre-leukemic condition
Clonal stem cell disorder with defective and ineffective hematopoiesis with increased risk of transformation to AML

Could be idiopathic or therapy related (after chemo)

20

Describe the pathophysiology of MDS

Hypercellular marrow with peripheral cytopenia
Cells are produced but they undergo apoptosis in the bone marrow itself, so they never make ti to the periphery

Could be cause by clonal cytogenetic abnormalities, stem cell damage, or morphologic abnormalities

21

What are the morphological abnormalities associated with MDS?

Nuclear irregularity
Nuclear budding
Multinucleation
Separated nuclear lobes

22

What is the prognosis of MDS?

Very bas
9-29 months for primary MDS, 4-8 months for secondary.

Subtypes of MDS with more blasts in the blood or marrow have a worse prognosis

23

What are the clinical findings of AML?

Anemias
Cytopenias
Abrupt stormy onset
Not much tissue involvement
Lower chance of CNS involvement

24

Acute Promyelocytic Leukemia (APL)
What mutation causes this disorder?

t(15;17)

25

How is APL related to DIC?

Procoagulants (tissue factor) may be released by leukemic cells to induce DIC in APL patients

26

What is the characteristic finding of APL on microscopic analysis?

Auer rods in the cytoplasm

27

Describe the pathogenesis of APL

t(15;17)
Leads to an abnormal RAR-a receptor, which blocks myeloid differentiation

28

What is the normal function of the RAR-alpha receptor?

Involved in activating the differentiation of myeloid cells

29

How could you treat APL with a t(15;17) mutation?

High doses of All-trans-retinoic acid (vitamin A derivative) will overcome the block of the RAR-alpha receptor

30

What two chemical stains may be used in the diagnosis of AML?

MPO

Alpha-naphthyl butyrate esterase

31

What markers should be looked at on flow cytometry for suspected AML?

Myeloid markers
CD13
CD33
CD34
CD117

32

What is an Auer rod? What does its presence tell you?

Auer rods are made of MPO which crystallizes and forms rod structures

Presence of Auer rod tells you it is a malignant myeloid cell

33

What is the prognosis of AML?

Depends on the chromosome abnormality

t(15;17) and t(8;21) have good prognosis

MLL translocations have a poor outcome

AMLs arising from MDS or chemotherapy have very poor prognosis

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