Chapter 12: Acute leukemias Flashcards Preview

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Flashcards in Chapter 12: Acute leukemias Deck (56):

What are leukemias?

Disorders characterized by the accumulation of white cells in the bone marrow and the blood


Why do leukemias causes disease?

(1) they cause bone marrow failure
(2) they infiltrate organs (liver, spleen, lymph nodes, meninges, brain, skin, testes.)


How are leukemias classified?

Leukemias are classified as acute or chronic, and further classified as lymphoid or myeloid.


What are acute leukemias?

Acute leukemias are aggressive diseases characterized by malignant transformation of hematopoietic stem cells or early progenitors.


What three general cellular abnormalities are often present in acute leukemias?

(1) increased rate of proliferation
(2) reduced apoptosis
(3) A block in cellular differentiation


What is the dominant clinical feature of acute leukemias?

accumualtion of blast cells in the bone marrow and peripheral blood along with bone marrow failure.


How is acute leukemia diagnosed?

Acute leukemia is diagnosed by the presence of over 20% blast cells in the blood or bone marrow.


How is acute leukemia sub-divided?

(1) acute myeloid leukemia (Myeloblasts)
(2) acute lymphoid leukemia (Lymphoblasts)


How is ALL differentiated from AML?

ALL usually shows no differentiation (except B cell ALL). AML typically shows a greater degree of differentiation.


What is hybrid acute leukemia?

Leukemias that show characteristics of both ALL and AML.


What is the epidemiology of ALL?

ALL is the most common leukemia in children. Peak age is 3-7 years old falling off after 10 years and rising slightly after 40 years old. T-ALL seems to favor males.


What are the three morphological clssifications of ALL?

(1) L1 has small blasts with scanty cytoplasm
(2) L2 has larger blast cells with more prominent nucleoli and cytoplasm
(3) L3 has largest blasts with prominent nucleoli, strongly basophilic cytoplasm and vacuoles.


Immunophenotyping can be used to differentiate ALL cells into what categories?

(1) Early pre-B
(2) Pre-B
(3) B-cell
(4) T-cell


What clinical features are associated with bone marrow failure caused by ALL?

(1) Anemia
(2) Neutropenia
(3) thrombocytopenia


What clinical features are associated with organ infiltration caused by ALL?

(1) Tender bones
(2) Lymphadenopathy
(3) Hepatosplenomegaly
(4) meningeal syndrome
(5) fever
(6) rarely testicular swelling or mediastinal compression.


What blood cell abnormalities are often seen with ALL?

Normochromic, normocytic anemia with thrombocytopenia. Hyper cellular bone marrow with over 20% blasts.


What abnormal biochemical test results may be caused by ALL?

(1) increased serum uric acid
(2) Increased serum lactate dehydrogenase
(3) rarely hypercalcemia
(4) Lytic bone lesions.
(5) enlarged thymus or lymph nodes (T-ALL)


What is the differential diagnosis for ALL?

(1) AML
(2) Aplastic anemia
(3) Marrow infiltration by other malignancies
(4) Infections (mono, pertusis)
(5) juvenile rheumatoid arthritis
(6) Immune thrombocytopenic purpura.


Why is cytogenetic and molecular genetic information concerning ALL significant?

Because the cytogenetic and molecular genetic characteristics of the malignancy profoundly impact prognosis.


What effect does ploidy have on ALL?`

Hyperdiploid (greater than 50 chromosomes) ALL generally has as good prognosis.
Hypodiploid ALL generally is associated with a poor prognosis.


What is the most common specific genetic abnormality in ALL?

t(12; 21) (p13; q22) TEL, AML1 translocation. This creates the TEL-AML1 fusion protein which suppresses normal AML1 which controls hematopoietic transcription.


What is the association between the philadelphia chromosome and ALL?

t(9; 22) philadelphia chromosome increases with age and is associated with a poor prognosis.


What gene is often translocated in infant leukemias?

The MLL gene


What is general supportive therapy for ALL?

treatment of bone marrow failure
(1) Central venous cannula
(2) Blood support
(3) prevention of tumor lysis syndrome
(4) fever must be treated promptly.


What therapies can be used to treat ALL?

(1) chemotherapy
(2) Radiotherapy.


What 4 basic treatment phases are used to treat ALL (excluding B-ALL)?

(1) remission induction
(2) Intensification (consolidation)
(3) Central nervous system directed therapy
(4) Maintenance


What is remission induction?

Remission induction is the attempt to kill most of the tumor cells and to induce remission (which is less than 5% blasts with no other signs or symptoms).


What drugs are used for remission induction?

(1) prednisolone or dexamethasone
(2) Vincristine
(3) asparaginase
(4) daunorubicin (only in adults)\
Remission is achieved in approximately 90% of patients


What is intensification/consolidation?

usually 2-3 courses of high dose multi-drug chemotherapy aimed at erradicating or reducing to very low number the amount of tumor cells.


What drugs are used for intensification?

(1) vincristine
(2) Cyclophosphamide
(3) Cytosine arabinoside (cytarabine)
(4) daunorubicin
(5) etoposide
(6) mercaptopurine


Why is CNS directed therapy necessary in ALL?

Because ALL will invade the CSF and most antineoplastics do not readily penetrate the CNS.


What drugs are used for CNS targeted therapy?

(1) High dose or intrathecal methotrexate
(2) C-ARA
(3) cranial irradiation (avoided in children)


What is maintenance therapy for ALL?

2 years (3 for young boys) of daily methotrexate, monthly vincristine (with 5 day oral corticosteroids)


What is done in patients being treated for ALL with persistent MRD?

Stem cell transplant or increased treatment intensity.


What specific treatments are indicated for patients with Ph( BCR-ABL) positive ALL?

(1) stem cell transplant
(2) Imatinib mesylate


What factors are associated with a good prognosis for ALL?

(1) low WBC
(2) Female
(3) B-ALL
(4) Child
(5) Normal or hyperploid cells
(6) rapid remission
(7) absent CNS disease
(8) MRD negative 1-3 months


What factors are associated with a poor prognosis for ALL?

(1) High WBC
(2) male
(3) T-ALL
(4) Adult
(5) Philadelphia chromosome
(6) slow remission
(7) CNS disease present
(8) MRD positive at 3-6 months
(9) relapse


What is the epidemiology of AML?

AML is common in adults and is increasingly common with age. (minor in childhood)


What is the difference between primary and secondary AML?

Primary AML appears to arise de novo. Secondary AML arises after myelodysplasis, chemotherapy, or other hematological disorders.


What is the most common genetic abnormality in AML?

The presence of tandem repeats of the FLT-3 gene.


How is AML classified?

There are 8 subtypes of
AML based on cytochemical staining, immunophenotype, and chromosomal changes.


What is the typical myeloid immunophenotype?

CD13+, CD33+, and TdT-


What are the clinical features of AML

(1) anemia
(2) Thrombocytopenia (thus bleeding)
(3) DIC (M3 variant)
(4) Gum hypertrophy, skin problems, and CNS disease (M4 and M5)


What is a granulocytic sarcoma?

An isolated mass of leukemic blasts.


What investigations are necessary for AML?

Genetic investigation is essential accurate prognosis and effective treatment.


What are the hematological findings for AML?

(1) anemia
(2) thrombocytopenia
(3) neutropenia


What are the biochemical findings for AML?

(1) increased serum uric acid
(2) Increased serum lactate dehydrogenase
(3) rarely hypercalcemia
(4) Lytic bone lesions.


What is M3 hemorrhagic syndrome?

Catastrophic hemorrhage, treatment is with platelet transfusion, FFP, and ATRA.


What is ATRA syndrome?

Due to neutrophilia that follows differentiation of promyelocytes.
Fever, hypoxia, pulmonary infiltrates, and fluid overload after administration.


What is the treatment for ATRA syndrome?

Dexamethasone twice daily. ATRA is only discontinued in the most severe cases.


How is specific therapy conducted for AML?

Four 1 week blocks of chemotherapy. Therapy is intensive and prolonged requiring supportive care. Induction --> consolidation --> consolidation --> Further consolidation or stem cell transplant.


What factors are associated with a poor prognosis for AML?

(1) Monosomy 5 or 7
(2) FLT-3 mutation
(3) Poorly responsive disease


What is the prognosis for AML in patients over 70?

Very poor especially if they have other health problems. However, if they are healthy remission can be achieved.


How is AML relapse treated?

AML relapse is treated with stem cell transplant in patients that can handle it and have a matching donor. Arsenic trioxide may be used for M3 relapse


What is the overall prognosis for AML?

(1) For children and young adults 50% achieve long term cure.
(2) for patients over 70 only 10% achieve a cure.


What form of Leukemia is associated with auer rods?

acute promyelocytic leukemia. (AML M3)