Blood Cancers Flashcards
Peripheral blood smear
PelgerHuët cells - dysplastic change which are abnormal appearing neutrophils having only two nuclear lobes
Dysplasia associated with myelodysplastic syndromes
PelgerHuet cells
Hypersegmented PMNs
Hypo/hypergranular cells
RBCs - presence of ringed sideroblasts (seen w/ prussian blue), megaloblastoid erythroid precursors, and mishapen erythroid precursors w/ nuclear budding
Megakarycytes may be abnormal and only have a single nuclear lobe or multiple separate nuclei (prawn ball megakaryocytes)
How are myelodysplastic syndromes classified?
Based on # of blasts present w/i marrow
WHO classification:
<5% blasts - MDS is either refractory anemia (RA) or RA w/ ring sideroblasts (RARS)
5-20% blasts in marrow - RA w/ excess blasts (RAEB)
> 20% blasts in marrow = acute leukemia
5q- syndrome
myelodysplastic syndrome which is characterized by megakaryocytes that are uniformly small and monolobated
Sxs of acute leukemia
Fever (secondary to infection), easy fatigability (due to anemia), and bleeding (due to thrombocytopenia)
Both ALL and AML are characterized by a decrease in mature forms of cells and increase in immature forms (blasts which have immature chromatin with multiple nucleoli)
Acute myelogenous leukemia
Epidemiology
Typically adults between ages of 15-39
Risk Factors:
-Akylating chemo
-Radiation
-Myelodysplastic syndromes
-Myeloproliferative neoplasms
-Down syndrome
CD markers for Pt w/ acute myelogenous leukemia
Myeloid markers:
CD13
CD33
Blast markers:
CD34
CD117
Myeloperoxidase (MPO) = stain to differentiate AML from ALL
Auer rods in AML
Abnormal lysosomal structures (primary granules) considered pathognomonic of myeloblasts
Stain red with MPO
Acute promyelocytic leukemia (APL)
APL is also characterized by the
translocation t(15;17), which results in the fusion of the retinoic acid receptor α (RARA) gene on chromosome 17 to the PML unit on chromosome 15
produces an abnormal retinoic acid receptor such that physiologic levels of retinoic acid no longer activate it.
Treatment for APL is with large doses of vitamin A derivatives, such as all-trans-retinoic acid, which inhibits the proliferation of cells of acute myeloid leukemia.
What subtype of acute myelogenous leukemia is associated with gingival infiltrates?
Acute monocytic leukemia
What subtype of acute myelogenous leukemia is associated with marked fibrosis of the bone marrow
Acute megakaryocytic leukemia is associated with acute myelofiborisis
Acute megakaryocytic leukemia is
associated in children younger than 5 years of age with Down syndrome.
Special stains for megakaryocytes include stains for von Willebrand factor and stains for GpIb/IIIa (on platelets).
Acute lymphoblastic leukemia (ALL)
Primarily disease of children and young adults
Lymphoblasts stain positively for TdT (nuclear enzyme)
ALL is associated with CNS infiltration (distinguishes from AML) where malignant lymphoblasts are protected from chemotherapy by the BBB
Pt’s with ALL may be given prophylactic radiation to head
Also, acute lymphoblastic leukemia is associated with Down syndrome after the age of 5
Immunologic classification of acute lymphocytic leukemia
Most of ALL are B-cell origin:
Lymphoblasts express CD19
Few cases are T-cell origin:
Lymphoblasts lack CD19 but instead express T-cell Ags (CD3 and CD7)
CD markers for T cells are CDs less than 10
Many cases of T-ALL involve a mediastinal mass (which may press on the esophagus causing dysphagia) and are clinically similar to cases of T-cell lymphoblastic lymphoma.
Pro B-cell ALL
+TdT (marker for immature cells)
Lacks CD10/cytoplasmic μ/surface Ig
Common B-ALL
+TdT and +CD10
CD10 is called CALLA - common ALL antigen
