Essential thrombocythemia: Difference between revisions
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== Definition == |
== Definition == |
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− | * Myelodysplastic disorder of the thrombocytopoeitic stem cells causing a clonal proliferation of thrombocytes |
+ | * [[Myelodysplastic disorder]] of the thrombocytopoeitic stem cells causing a clonal proliferation of thrombocytes |
− | == |
+ | == Clinical Manifestations == |
− | |||
⚫ | |||
− | |||
− | == Clinical Presentation == |
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* History |
* History |
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** Increased cardiovascular risk |
** Increased cardiovascular risk |
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** Older than 60 years |
** Older than 60 years |
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+ | |||
+ | == Differential Diagnosis == |
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⚫ | |||
+ | |||
+ | == Investigations == |
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+ | |||
+ | * CBC with peripheral blood film shows thrombocytosis with platelet anisocytosis |
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+ | ** RBCs usually normochromic and normocytic, unless there is concurrent [[iron deficiency anemia]] |
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+ | ** [[Leukoerythroblastic reaction]] suggests post-ET [[myelofibrosis]] |
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+ | * Bone marrow aspiration and biopsy shows normal cellularity or moderate hypercellularity with large megakaryocytes |
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+ | ** Findings that suggest an alternative diagnosis include highly atypical megakaryocytes, increased myeloblasts, myelodysplastic features, or significant reticulin fibrosis or collagen fibrosis |
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+ | * Genetic testing |
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+ | ** JAK2 in 60-65% |
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+ | ** CALR in 20-25% |
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+ | ** MPL in 5% |
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+ | ** Triple-negative (all above negative) in 10-15% |
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+ | *Send BCR-ABL testing to exclude [[CML]] |
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+ | |||
+ | == WHO Diagnostic Criteria == |
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+ | |||
+ | * Diagnosis require 4 major criteria or the first 3 major criteria plus the minor criterion |
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+ | * Major criteria |
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+ | ** Platelets ≥450 |
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+ | ** Bone marrow biopsy showing proliferation of megakaryocytes with increased numbers of enlarged, mature megakaryocytes with hyperlobulated nuclei; and no significant increase or left shift in neutrophil granulopoiesis or erythropoiesis and very rare minor increase in reticulin fibers |
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+ | ** Not meeting WHO criteria for BCR-ABL1 CML, PV, PMF, myelodysplastic syndrome, or other myeloid neoplasms |
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+ | ** Presence of JAK2, CALR, or MPL mutation |
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+ | * Minor criterion |
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+ | ** Presence of a clonal marker or abscence of evidence for reactive thrombocytosis |
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== Management == |
== Management == |
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* Acute |
* Acute |
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− | ** If digital or cerebrovascular ischemia, rapid cytoreduction with |
+ | ** If digital or cerebrovascular ischemia, rapid cytoreduction with platelet pheresis |
* Chronic |
* Chronic |
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− | ** If high risk, requires cytoreduction and aspirin: |
+ | ** If high risk, requires cytoreduction and [[aspirin]]: |
− | *** First-line: hydroxyurea |
+ | *** First-line: [[hydroxyurea]] |
− | *** Alternative: anagrelide |
+ | *** Alternative: [[anagrelide]] |
− | *** Pregnancy: interferon alfa |
+ | *** Pregnancy: [[interferon alfa]] |
** If >1.5m platelets, requires cytoreduction alone |
** If >1.5m platelets, requires cytoreduction alone |
||
Latest revision as of 09:30, 23 August 2023
Definition
- Myelodysplastic disorder of the thrombocytopoeitic stem cells causing a clonal proliferation of thrombocytes
Clinical Manifestations
- History
- History of thrombosis or bleeding
- Signs & Symptoms
- Digital ischemia
- Cerebrovascular ischemia
- High risk for vascular events if:
- History of thrombosis or bleeding
- Increased cardiovascular risk
- Older than 60 years
Differential Diagnosis
- Must distinguish from other myelodysplastic disorders (especially polycythemia vera) as well as from secondary causes of thrombocytosis
Investigations
- CBC with peripheral blood film shows thrombocytosis with platelet anisocytosis
- RBCs usually normochromic and normocytic, unless there is concurrent iron deficiency anemia
- Leukoerythroblastic reaction suggests post-ET myelofibrosis
- Bone marrow aspiration and biopsy shows normal cellularity or moderate hypercellularity with large megakaryocytes
- Findings that suggest an alternative diagnosis include highly atypical megakaryocytes, increased myeloblasts, myelodysplastic features, or significant reticulin fibrosis or collagen fibrosis
- Genetic testing
- JAK2 in 60-65%
- CALR in 20-25%
- MPL in 5%
- Triple-negative (all above negative) in 10-15%
- Send BCR-ABL testing to exclude CML
WHO Diagnostic Criteria
- Diagnosis require 4 major criteria or the first 3 major criteria plus the minor criterion
- Major criteria
- Platelets ≥450
- Bone marrow biopsy showing proliferation of megakaryocytes with increased numbers of enlarged, mature megakaryocytes with hyperlobulated nuclei; and no significant increase or left shift in neutrophil granulopoiesis or erythropoiesis and very rare minor increase in reticulin fibers
- Not meeting WHO criteria for BCR-ABL1 CML, PV, PMF, myelodysplastic syndrome, or other myeloid neoplasms
- Presence of JAK2, CALR, or MPL mutation
- Minor criterion
- Presence of a clonal marker or abscence of evidence for reactive thrombocytosis
Management
- Acute
- If digital or cerebrovascular ischemia, rapid cytoreduction with platelet pheresis
- Chronic
- If high risk, requires cytoreduction and aspirin:
- First-line: hydroxyurea
- Alternative: anagrelide
- Pregnancy: interferon alfa
- If >1.5m platelets, requires cytoreduction alone
- If high risk, requires cytoreduction and aspirin: