Intro to Leukemias Flashcards
Describe leukemia
Progressive, malignant disease of hematopoietic system
What characterizes leukemia?
Unregulated proliferation of typically 1 type of cell line in the bone marrow.
Where does leukemia start?
In the bone marrow and spread into peripheral blood.
How is leukemia grouped?
By cell lineage and by maturity of affected cells (acute or chronic)
Describe the approach of leukemia treatment.
Treat the whole patient not just one part because the disease is systemic in nature.
Acute leukemia is characterized by…?
The abnormally large number of immature cells.
Gap in normal maturation process in bone marrow
Sudden onset
Aggressive short disease pattern
Lots of infection and hemorrhaging
FAB defines acute leukemia by
Greater than 30% blasts in bone marrow
WHO defines acute leukemia by
Greater than 20% blasts in bone marrow
Chronic Leukemia is characterized by…
-All stages of maturation seen (mostly mature cells)
-Insidious onset
-Longer, less aggressive disease pattern that involves organ infiltration and massive leukocytosis
-Sometimes can turn into acute called blast crisis
FAB defines chronic leukemia as….
Less than 30% blasts in bone marrow
WHO defines chronic leukemia as…
Less than 20% blasts in bone marrow
Which age groups are vulnerable to acute leukemia?
All ages are vulnerable
Which age groups are vulnerable to acute leukemia?
All ages are. Adults have poor outcomes.
WBC count in acute leukemia is
variable, can be very low
WBC count in chronic leukemia can be…
High
Platelet counts in acute leukemia is
variable sometimes very low
Platelet counts in chronic leukemia can be
Normal to elevated
Between acute or chronic leukemia which is severe?
Chronic leukemia
What does FAB stand for and what does it do?
French-American-British system established to provide uniform criteria for classifying acute leukemias before treatment changed their cellular morphology.
Other goals
-Aid in correlating treatment response to outcome and prognosis
-Differentiating different leukemias
In the modified FAB system, what changed?
Emphasis on correlating cytogenetic and immunochemistry studies with specific leukemia subtypes and clinical outcomes. All this work is for fine tuning treatment modalities.
Note: FAB has difficulty classifying platelet disorders, lymphoproliferative disorders, and variant monoblastic presentations.
What are the four methodologies used for identifying and classifying leukemias?
- Morphologic review of bone marrow and peripheral blood smears
- Cytochemical stains such as NSE, LAP, etc.
- Immunophenotyping
- Cytogenetic & molecular analyses
What information does morphologic review of bone marrow and peripheral blood smear yield?
Bone marrow - useful for differentiating acute versus chronic.
Peripheral blood smear - Limited diagnostic utility and usually sent out for pathology review.
What information does cytochemical stains yield?
Identifies specific molecules in malignant cells ( e.g. lipids, enzymes) that are associated with specific cell lines.
Note: This lead to immunophenotyping and cytogenetic analysis.
What information does immunophenotyping yield?
Uses flow cytometry with fluorescent antibodies to get information about surface marker antigens/receptors, cytoplasmic proteins, and nuclear information.
What enzyme increase suggests all lymphoblastic leukemias
Terminal deoxynucleotidyl transferase (TdT)
Note: Not typically seen in AML (?) per slide 13
What does it mean if a tumor is aneuploid?
Increase risk of relapse
What techniques/methods are used in cytogenetic and molecular analyses of leukemias?
- Karyotyping
- FISH, Fluorescence in Situ Hybridization
- PCR
What is the purpose of using PCR in molecular analyses in leukemias?
Yields quantitative results. Normal gene rearrangement means no malignancy. Positive translocation means there is malignancy.
What is karyotyping?
Why is FISH used in cytogenetic and molecular analysis of leukemias?
Its an excellent tool to detect micro-deletion syndromes caused by mismatch during crossing over. Examples are alpha thalassemias or DiGeorge Syndrome.
What does ALL stand for?
Acute lymphoblastic. Less specifically, lymphocytic leukemia
What does CLL stand for?
Chronic lymphocytic leukemia
What does AML stand for?
Acute myeloblastic. Less specifcally, myelocytic or myeloid.
What does ANLL stand for?
Acute nonlymphocytic leukemia
What does CML stand for?
Chronic myelocytic / myelogenous / myeloid leukemia
What are the four known causes of malignancies?
- Genetics
- Leukemogens
- Viral infections
- Radiation
In the cases of malignancies caused by genetics they are usually…
Somatic translocation and aneuploidy
What is the etiology of leukemogens?
Chemicals causing bone marrow depression and aplasia predispose to leukemia later on in life.