ALL

Question 1

1. Contrast acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) in regards to demographics of affected patients, and prognosis.

Answer 1

AML = Affects adults mostly
ALL = Affects children mostly with good cure rate.  Rarer in adults where prognosis is worse

Question 2

Explain the concept of a “leukemic stem cell”.

Answer 2

in patients with acute leukemia there is a population of self-renewing cells that, in essence, provides an inexhaustible source of the leukemic cells that replace the bone marrow.

Question 3

3. List risk factors for acute leukemia, while recalling that the majority of acute leukemias occur in the apparent absence of risk factors.

Answer 3

• Previous chemotherapy, especially DNA alkylating agents and topoisomerase-II inhibitors
• Marrow exposure to ionizing radiation

Others…

• Tobacco smoke
• Benzene exposure
• Genetic syndromes including Down syndrome, Bloom syndrome, Fanconi anemia, and ataxia-telangiectasia.

Question 4

List common signs and symptoms exhibited by patients with acute leukemia at initial presentation, and explain the reasons for these findings.

Answer 4

Present because of normal marrow replacement, so:
- Anemia: fatigue, malaise, pallor, dyspnea
- Thrombocytopenia: bruising, petechiae, hemorrhange
- Neutropenia: fever, infections
OR
Directly attributable to leukemic cells
- High WBC count = Inc viscosity = Thrombotic event
- DIC: clotting & clot-lysis = strokes, bleeding
- Direct infiltration of tissues (skin, gums)

Question 5

List methods for immunophenotyping in acute leukemias, and list a few basic markers that would help to assign blasts to a precursor-B, precursor-T, or myeloid lineage.

Answer 5

Take biopsy and add Ab (IHC) or flow 
CD34 = immaturity
TdT = Common LYMPHOBLAST
Bcell = CD19 CD22 (lack Ig & CD20, mature)
Tcell = CD3 CD7

Question 6

Contrast B-ALL and T-ALL in regards to patient age and sex, manner of manifestation, and prognosis.

Answer 6

In contrast to B-ALL, T-ALL…

• adolescents & young adults
• Component of T-LBL (mediastinal mass)
• Markedly elevated WBC
• Favors males

Question 7

List 3 commonly observed cytogenetic abnormalities in B-ALL, and recall the usual patient age group and prognosis associated with these abnormalities.

Answer 7

9;22 BCR-ABL: “Philly” / Adults / WORST prognosis
MLL (11q23): neonates & infants; poor prog
t(12;21); childhood; very good prog

Question 8

List 5 factors affecting prognosis in ALL.

Answer 8

Worst prognosis for…

• Age: worst for 10, adults
• WBC count: markedly elevated at Dx
• Slow response to therapy / small amounts of residual disease after therapy
• # of chromosomes: hyper (50-66) is good, hypo (<46) is bad
• B vs. T: T-ALL is worse