3 Childhood Leukemias Flashcards
The myeloid and lymphoid cell lines are derived from the
pluripotent stem cells, that can differentiate into nearly all cells
Examples of chromosomal breakage syndromes that could cause children to be at increased risk of developing leukemia
Fanconi anemia, bloom syndrome, ataxia telangectasia, diamond blackfan, noonan syndrome, kostmann syndrome, klinefelters, dyskeratosis congenita, familial platelet disorder
ALL vs AML incidence
ALL 75% leukemia, and about 1/4 of childhood cancer. AML is about 15% childhood leukemia and about 5% of all childhood cancers
5 year relative survival rate of ALL? AML?
ALL - 89%, AML - 60%
‘extramedullary involvement’ means
blasts spilled outside of the marrow
What is a chloroma
leukemic cell infiltration sometimes found in soft tissues, bones etc. More commonly invading the skin in AML. They are slightly green when excised or exposed to air. Potential to cause cord compression or visual loss depending on placement.
What percent of children with leukemia will present with a normal CBC?
10%
Elevated potassium, phosphorus, and uric acid may be?
Low calcium or high creat?
Elevated LDH?
Could all be signs of tumor lysis syndrome
Signs of DIC? (lab values)
Elevated PT/PTT, low fibrinogen, elev D Dimer
When is it ideal to get HLA typing?
(only for high risk patients who might need transplant) prior to Chemo since it usually involves WBCs
All children with suspected leukemia have a 5-10% chance of presenting with ___ and should get a rule out ____
mediastinal mass, CXR. Could cause obstruction when doing initial procedures
4 major types of tests done on bone marrow at diagnosis
Morphology, Cytochemistry, Immunophenotyping, and cytogenetics
What is morphology?
The form and structure of the cells. Leukemic cells are ‘hypercellular/packed’ and percentage of blasts is determined,
Erythroid- RBC, Granulocytic - WBC, Megakaryocytic - PLT
What is cytochemistry?
helps determine ALL vs AML among other things, differentiates AML subtypes
What does immunophenotyping (aka flow cytometry) identify?
Antigens on blasts, also help differentiate AML and ALL as well as subtypes
What does ‘CD’ stand for as a monoclonal antibody precurser?
‘cluster of differentiation’. monoclonal antibodies have been developed that react with lineage specific lymphoid and myeloid activation and differentiation antigens
What does cytogenetics measure?
marrow cells are grown in a culture and analyzed for chromosome and structure, deletions, translocations, etc.
Childhood ALL, what percentage B cell vs T cell?
B cell 85%, T cell 15%.
Which subtype of ALL is associated with very high WBC and mediastinal mass? Who is it most commonly affecting?
T cell. more common in adolescent boys.
What is Mature B Cell?
Burkitt. Responds poorly to ALL thereapy, but do well when treated with Burkitt lymphoma therapy
Which is generally favorable, hyperdiploidy or hypodiploidy?
Hyperdiploidy (extra copies) is usually favorable.
Children with a presenting WBC higher than _______ generally have a poorer diagnosis
50,000
Favorable or unfavorable: TEL-AML? Mixed Lineage Leuk (MLL) BCR/ALB (phil chromosome) Trisomy 4,10
t(12;21): associated with the TEL-AML1 gene product and conferring a very favorable prognosis; this translocation is most common in B precursor ALL and is associated with >90% chance of long-term survival
t(4;11): associated with the MLL gene product and a very poor prognosis, most often seen in infant ALL
t(9;22): associated with the BCR/ABL gene product and known as the “Philadelphia chromosome (Ph+)”
This type of ALL responds poorly to standard therapy and historically has been associated with poor outcomes. However, recent advances in targeted therapy appear to be improving the outlook for these patients.
Trisomy (an extra copy of the entire chromosome) of chromosomes 4 and 10 is associated with an excellent outcome in childhood ALL.
Favorable age at diagnosis in ALL?
Between the ages of 2-10. Infants usually do the worst.