90 Acute Lymphoblastic Leukemia Flashcards
TRUE OR FALSE
Most cases of ALL occur in children, but most deaths from ALL occur in adults.
TRUE
Most cases of ALL occur in children, but most deaths from ALL occur in adults.
Heritable cancer predisposition syndromes associated with increased ALL
Li Fraumeni syndrome with germline TP53 mutation
Approximately 61% of patients with ALL are diagnosed before the age of _________
before the age of 20 years
Only 20% of adult acute leukemias are ALL, but about one-third of ALL cases are in adults
Almost all ALL patients with Down syndrome have a deletion of
IKZF1.31
Genetic abnormalities more commonly associated with Down syndrome, such as +X, del(9), and CEBPD rearrangement
Autosomal recessive genetic diseases associated with increased chromosomal fragility and a predisposition to ALL include:
Ataxia-telangiectasia
Nijmegen breakage syndrome
Bloom syndrome
These genes are key regulators of blood cell development, and acquired mutations of each are also detected in ALL cases
Consistently associated with childhood ALL
IKZF1, ARID5B, CEBPE, and CDKN2a
The hypothesis that suggests that some susceptible individuals with a prenatally acquired preleukemic clone had low or no exposure to common infections early in life because they lived in affluent hygienic environments.
Such infectious insulation predisposes the immune system of these individuals to aberrant or pathologic responses after subsequent or delayed exposure to common infections at an age commensurate with increased lymphoid cell proliferation.
“Delayed infection” hypothesis
The hypothesis that predicts that clusters of childhood ALL result from exposure of susceptible (nonimmune) individuals to common but fairly nonpathogenic infections after population mixing with carriers.
“Population-mixing” hypothesis
The most frequent genetic (chromosomal) abnormality in ALL
Translocations
Most common genetic abberations in childhood
Hyperdiploidy (>50 chromosomes)
23-29%
2nd: t(12;21)(p13;q22) [ETV6-RUNX1] 20–25%
Most common genetic abberations in adults
t(9;22)(q34;q11.2) [BCR-ABL1]
25–30%
Genetic abnormalities found in T-cell ALL
NOTCH1 mutations
HOX11L2 overexpression
LYL1 overexpression
TAL1 overexpression
HOX11 overexpression
Encodes a paired-domain protein required for the pro–B-cell to pre–B-cell transition and B-lineage fidelity
Most frequent target gene in ALL
PAX5
Second most frequently involved gene
Required for the earliest lymphoid differentiation
IKZF1
IKZF1 was deleted in the vast majority of cases of BCR-ABL1 ALL cases as well as chronic myeloid leukemia in lymphoid blast crisis (but not chronic phase).
Very poor outcome
Contributes to treatment resistance in ALL
Intracranial hemorrhage occurs mainly in patients with an initial leukocyte count greater than
400 × 109/L
Most common sites of extramedullary involvement, and the degree of organomegaly is more pronounced in children than in adults
Liver, spleen, and lymph nodes
Overt testicular disease can be readily diagnosed by
Ultrasonography
TRUE OR FALSE
Overt testicular disease is relatively rare, is generally seen in adults with B-cell leukemia and/or hyperleukocytosis, and does require radiation therapy.
FALSE
Overt testicular disease is relatively rare, is generally seen in infants or adolescents with T-cell leukemia and/or hyperleukocytosis, and does not require radiation therapy.
Patients with hyperleukocytosis are more likely to have _______________ ALL
T-cell ALL
Hyperleukocytosis occurs more often in black children (23%) and in adults (16%)
TRUE OR FALSE
Hypereosinophilia, generally reactive, may precede the diagnosis of ALL by several months.
TRUE
Hypereosinophilia, generally reactive, may precede the diagnosis of ALL by several months.
- Mostly male
- Have ALL with the t(5;14)(q31;q32) chromosomal abnormality and a hypereosinophilic syndrome (pulmonary infiltration, cardiomegaly, and congestive heart failure)
Coagulopathy, usually mild, can be seen in 3% to 5% of patients, most of whom have ____ ALL, and is only rarely associated with clinical bleeding
T-cell ALL
Translocation found in 0.5% of B-cell precursor ALL, is associated with adolescent age, disseminated coagulopathy, hypercalcemia, and dismal prognosis.
t(17;19)(q22;p13.3) with E2A-HLF fusion
TRUE OR FALSE
Examination of the cerebrospinal fluid (CSF) is an essential diagnostic procedure.
TRUE
Examination of the cerebrospinal fluid (CSF) is an essential diagnostic procedure.
Leukemic blasts can be identified in as many as one-third of pediatric patients and approximately 5% of adult patients at diagnosis of ALL; most of these patients lack neurologic symptoms.
Most protocols now require the procedure at diagnosis and instill the first dose of chemotherapy intrathecally.
Morphologic characteristics of lymphoblasts
Small (ranging from the same size to twice the size of small lymphocytes), with scanty, often light-blue cytoplasm, a round or slightly indented nucleus, fine to slightly coarse and clumped chromatin, and inconspicuous nucleoli
Are characterized by intensely basophilic cytoplasm, prominent nucleoli, and cytoplasmic vacuolation
B-cell blasts in Burkitt-type ALL
Typical panels include antibodies to at least one highly sensitive marker and antibodies to a highly specific marker
Highly sensitive markers:
CD19 for B-cell lineage
CD7 for Tcell lineage, and
CD13 or CD33 for myeloid cells
Highly specific markers:
cytoplasmic CD79a and CD22 for B-cell lineage,
cytoplasmic CD3 for T-cell lineage, and
cytoplasmic myeloperoxidase for myeloid cells
Immunologic Subtype of ALL
Infants and adult age group, high leukocyte count, initial CNS leukemia, pseudodiploidy, MLL rearrangement, unfavorable prognosis
Pro-B
Immunologic Subtype of ALL
Favorable age group (1–9 years), low leukocyte
count, hyperdiploidy (>50 chromosomes)
Early pre-B
Immunologic Subtype of ALL
High leukocyte count, black race, pseudodiploidy
Pre-B
Immunologic Subtype of ALL
Male predominance, initial CNS leukemia, abdominal masses, often renal involvement
Mature B cell (Burkitt)
Immunologic Subtype of ALL
Male predominance, hyperleukocytosis, extramedullary disease
T Cell