Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
35 Cards in this Set
- Front
- Back
|
What are the four general categories of bone marrow stem cell disorders?
|
Aplastic anemia (not neoplastic)
Myelodysplastic syndromes (clonal neoplastic disorder) Chronic myeloproliferative disorders (cnd) Acute leukemia (cnd) |
|
|
Which two general categories of bone marrow stem cell disorders causes cytopenias?
|
Aplastic anemia and myelodysplastic syndrome
|
|
|
How do the cytopenias caused by aplastic anemia (AA) and myelodysplastic syndrome (MDS) differ?
|
AA affects more types of cells (pancytopenia)
MDS could have one or more cytopenias, but typically not as many; the cells also have abnormal function |
|
|
What is aplastic anemia?
|
Stem cells don't proliferate as well
Pancytopenia with bone marrow hypocellularity |
|
|
Define severe AA?
|
Neutrophils < 500/uL
Platelets <20,000/uL Reticulocytes < 50,000/uL |
|
|
What are the two types of AA? Which is more common?
|
Idiopathic (primary)
Secondary (drugs, radiation, other marrow toxins) They are about even in prevalence |
|
|
What is MDS?
|
Clonal myeloid stem cell disorder
Usually present with cytopenia(s) Some progress to acute myelocytic leukemia |
|
|
What kind of labs should you get if you suspect MDS?
|
Blood and bone marrow smear morphology for evidence of dysplasia and blast count
vitamin B12/folate deficiencies can mimic MDS, so you want to exclude those Cytogenetics/molecular genetics for evidence of clonality |
|
|
What are some histological signs of MDS?
|
Ring sideroblasts (problem in iron handling)
Dysmorphic erythroid precursors (nuclear irregularity) Dysmorphic granulocytes (hypogranular cytoplasm, hyposegmented nuclei) Dysmorphic megakaryocate (hypolobulated nuclei) Dysmorphic platelets (giant, hypogranular) |
|
|
Describe chronic myeloproliferative disorders (CMPDs).
|
Clonal myeloid stem cell disorders that often present with elevated peripheral counts but don't usually have dysplasia
|
|
|
What should you distinguish CMPDs from?
|
Reactive proliferations such as:
neutrophilia/leukemoid reaction Secondary polycythemia Reactive thrombocytosis |
|
|
What are some clues to diagnosis of a leukemoid reaction?
|
Toxic granulation and Dohle bodies with normal cytogenetics/molecular genetics
|
|
|
How do you distinguish chronic myeloproliferative and chronic lymphoproliferative disorders from acute myeloid and acute lymphoid leukemias?
|
KNOW
Acute problems are generally from a block in maturation, so you're going to see an increased proportion of very immature cells (blasts). In chronic problems, you'll see more differentiated leukocytes |
|
|
Which is worse: chronic myeloproliferative and chronic lymphoproliferative disorders or acute myeloid and acute lymphoid leukemias?
|
Acute problems by far, rapidly fatal
Chronic isn't too bad |
|
|
What are four CMPDs?
|
Chronic myelogenous leukemia (CML)
Polycythemia vera (PV) Primary myelofibrosis (myelofibrosis with myeloid metaplasia) Essential thrombocythemia (ET) |
|
|
What are some features of CML?
|
Blood and bone marrow proliferation of differentiated myeloid cells with left shift but few blasts
Blood and bone marrow basophilia Philadelphia chromosome or molecular equivalent (BCR/ABL fusion) Although CML originates in the multipotent stem cell, granulocytic elements constitute the dominant cell line |
|
|
What does "left shift" mean?
|
Means that cell production is shifted towards immaturity
|
|
|
What is the Philadelphia chromosome?
|
Translocation from 22 to 9
|
|
|
What are some features of polycythemia vera?
|
Increase in RBC, hemoglobin, and hematocrit (this increases blood viscosity and leads to thrombotic/hemorrhagic complications)
Hypercellular bone marrow (panmyelosis) Moderate leukocytosis/thrombocytosis is common Associated with decreased erythropoietin levels |
|
|
What mutation is extremely common in PV?
|
JAK2 V617F mutation
|
|
|
What are some features of primary myelofibrosis?
|
Bone marrow becomes progressively fibrotic and hypocellular with extramedullary hematopoiesis (spleen and liver); splenomegaly
Leukoerythroblastic peripheral blood smear |
|
|
What mutation is common in primary myelofibrosis? How common?
|
JAK2 V617F, 50%
|
|
|
What is the cause of primary myelofibrosis?
|
Abnormal marrow stem cell replication that leads to fibrosis (replacement of marrow with collagen)
|
|
|
What are some features of essential thrombocythemia (ET)?
|
Least common of the 4 CMPDs
Sustained platelet count over 450,000/uL Normal RBC mass No Philadelphia chromosome No or limited marrow fibrosis JAK2 V617F back for more, 50% of cases |
|
|
How do you diagnose essential thrombocythemia?
|
Numerous abnormal megakaryocytes in bone marrow
Platelets morphologically bizarre and dysfunctional Exclusion of all other causes of thrombocytosis (inflammation, iron deficiency, malignancies, post-splenectomy) |
|
|
What are some characteristics of acute leukemias?
|
Bone marrow largely replaced with blasts
Leukemic blasts in peripheral blood may lead to elevated WBC Leukemic cells may infiltrate liver, spleen, lymph nodes, skin, and other tissues |
|
|
What is the laboratory evaluation of acute leukemias?
|
Anemia, neutropenia, and thrombocytopenia (could be complicated by coagulopathy)
Specialized studies for subclassification (cytochemistry, flow cytometry, cytogenetics/molecular genetics) |
|
|
What is the current definition of acute leukemia?
|
>20% blasts in bone marrow and/or peripheral blood
|
|
|
What are some features of acute lymphoblastic leukemia (ALL)?
|
Much more common in kids
Flow cytometry is useful to determine immunologic subtypes (B- vs T-lineage), which can have prognostic significance Cytogenetic/molecular genetic changes - prognostic importance (Philadelphia chromosome confers poor prognosis) |
|
|
What are some features of acute myeloblastic leukemia (AML)?
|
More common in adults
Myeloblasts have Auer rods, unlike lymphoblasts (good way to distinguish ALL and AML) |
|
|
What are Auer rods?
|
Crystalline array of MPO
|
|
|
What is a subtype of AML that has specific cytogenetic abnormalities and prognostic implications?
|
FAB M3-acute promyelocytic leukemia
Numerous Auer rods 17 to 15 chromosomal translocation High risk of DIC Great response to retinoic acid treatment |
|
|
How are cytochemical stains helpful?
|
MPO is evidence of granulocytic differentiation
Nonspecific esterase is evidence of monocytic differentiation |
|
|
How is flow cytometry useful?
|
To distinguish AML from ALL
|
|
|
How are cytogenetic/molecular genetic changes useful?
|
May have diagnostic and prognostic importance
|
