Acute leukaemia types: Difference between revisions
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* Expression of one or more of CD117, CD33, CD13 markers on otherwise typical ALL is allowed and does not change lineage assignment | * Expression of one or more of CD117, CD33, CD13 markers on otherwise typical ALL is allowed and does not change lineage assignment | ||
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|colspan="1" style = "font-size:90%; color:black;" |'''[[CD117]]''' | |colspan="1" style = "font-size:90%; color:black;" |'''[[CD117]]''' |
Revision as of 09:23, 7 October 2023
- Expression of one or more of CD117, CD33, CD13 markers on otherwise typical ALL is allowed and does not change lineage assignment
|- |colspan="1" style = "font-size:90%; color:black;" |CD117 |colspan="1" style = "font-size:84%;"|An early marker of myeloid lineage, seen in up to 80% of AML and vauable in recognising more primitive differentaiion forms (note that aberrant expression is seen in up to 20% of ALL cases) |- |colspan="1" style = "font-size:90%; color:black;" |CD33 |colspan="1" style = "font-size:84%;"|A good marker for AML, particularly for those cases with granulocytic maturation, CD33 is often less strongly expressed in AML with monocytic dfferentiation and strongly expressed in APL. |- |colspan="1" style = "font-size:90%; color:black;" |CD13 |colspan="1" style = "font-size:84%;"|A good lineage marker for AML that is acquired a little later in differentation than CD117 or CD33; expression of CD13 is often higher than CD33 in AML with monocytic differentiation. |- |}
WHEN SHOULD ALTERNATIVE OR AMBIGUOUS LINEAGE BE ASSIGNED?
This occurs if:
- Any myeloid lineage-defining markers are present and B-Lymphoid and/or T-lymphoid defining markers are also present
or
- At least two myeloid lineage-associated markers are present but also 'two markers of B-lymphoid and/or T-lymphoid lineage
OR
- Cells have no more than one lineage-associated marker of any lineage
Sections
- Markers of "primitive nature": go to section
- Core markers of most cases: go to section
- Aberrant markers often seen: go to section
- Notes 1: specific subtypes: go to section
- Notes 2: ambiguous lineage go to section
(note: for further information on any marker or section click the blue highlighted text)
.
MARKERS USEFUL TO CONFIRM MYELOID LINEAGE OR DIFFERENTIATION | |
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Confirmatory markers of AML or markers of subtype
| |
Granulocytic lineage markers | |
CD10 | One of tne of the first lineage-markers acquired in AML with good relative specificity |
CD11b | One of tne of the first lineage-markers acquired in AML with good relative specificity |
Monocytic lineage markers | |
CD11c | One of tne of the first lineage-markers acquired in AML with good relative specificity |
CD14 | A good marker for AML that is often less strongly expressed in monocytic forms |
CD64 | A good lineage marker for AML aquired a little later, higher than CD13 in monocytic forms |
Features associated with erythroid differentiation | |
Most often CD34, CD45 and HLA-DR are weak or negative, although CD117 and CD36 are generally expressed. There may be some expression of platelet markers in some cases. | |
CD71 | Frequently expressed though not fully lineage specific |
CD235 | A good marker of erythroid differentiation but acquired late and therefore may not be expressed |
Features associated with megakaryocytic differentiation | |
Most often CD34, CD45 and HLA-DR are weak or negative, although CD13 and CD33 may be expressed | |
CD41 | Platelet glycoprotein IIbIIIa |
CD61 | Platelet glycoprotein IIIa |
CD42b | Platelet gycoprotein Ib |
CD36 | Relatively non-specific (seen in erythroid and monocytic leukaemias) but often strongly expressed
|
.
NON MYELOID MARKERS FREQUENTLY "ABERENTLY" EXPRESSED IN AML | |
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Markers of lymphoid lineage indicating primitive dfferentiation in AML
| |
TDT | Expressed in some cases of AML (5-20%) particularly in less differentiated blast cells, often on a sub-population of cells. More typically associated with primitive ALL blast cells. |
CD7 | Predominantly seen as a T-cell antigen, CD7 tends may be expressed by AML blasts (20-40%) where it most often indicates a more primitive forms or MPAL. CD7 is most consistently a marker of T-lineage (including T-ALL and more mature froms). |
Markers of lymphoid differentation abererantly expressed in AML
| |
TDT | Expressed in some cases of AML (5-20%) particularly in less differentiated blast cells, often on a sub-population of cells. More typically associated with primitive ALL blast cells. |
CD7 | Predominantly seen as a T-cell antigen, CD7 tends may be expressed by AML blasts (20-40%) where it most often indicates a more primitive forms or MPAL. CD7 is most consistently a marker of T-lineage (including T-ALL and more mature froms). |
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IMPORTANT ADDITIONAL POINTS 1 | |
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AML subtypes with distinctive phenotype
(1) Typically AML blasts have low CD45 expression and cause low side scatter. This means that they form a relatively uniform and distinctive population that is clearly separate from that of lymphocytes on CD45/SSc plots (for further details see this section) also not all AML forms may fit this pattern - particularly APL and monocytic AML. | |
Mixed Phenotype Acute leukaemia (MPAL) | |
Formerly known as leukaemia of ambiguous lineage | |
Early T-precursor acute lymphoblastic leukaemia (ETP-ALL) | |
A (relatively new entity) |
.
IMPORTANT ADDITIONAL POINTS 2 | |
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Acute leukaemias with ambiguous lineage features
(1) Typically AML blasts have low CD45 expression and cause low side scatter. This means that they form a relatively uniform and distinctive population that is clearly separate from that of lymphocytes on CD45/SSc plots (for further details see this section) also not all AML forms may fit this pattern - particularly APL and monocytic AML. | |
Mixed Phenotype Acute leukaemia (MPAL) | |
Formerly known as leukaemia of ambiguous lineage: Myeloid MPO or monocytic defined by at least two markers (CD14, CD11c, CD64, NSE, lysozyme. T lineage CD3 (s or m), STRONG Cd19, with strong CD79a cCD22 or CD10 OR wk CD19 also with obove | |
Early T-precursor acute lymphoblastic leukaemia (ETP-ALL) | |
A (relatively new entity) | |
Undifferentiated acute leukaeemia | |
A (relatively new entity) | |
Non-haematopoietic tumours | |
need to know problems |