View source for Essential thrombocytosis

==Background==
*Rare, chronic [[myeloproliferative disorders|myeloproliferative neoplasm]]
*Abnormal proliferation is seen in megakaryocytic line only
*Typically in elderly
*Generally asymptomatic

==Clinical Features==
*[[Leukocytosis]]
*[[Anemia]]
*Splenomegaly
*Clotting or [[coagulopathy|bleeding]]

==Differential Diagnosis==
*[[Myelofibrosis]]
*[[Chronic myelogenous leukemia]] (CML)
*[[Polycythemia vera]] (PV)
===Reactive thrombocytosis===
* Acute [[hemorrhage|blood loss]]	
* Acute [[hemolytic anemia]]
* Iron deficiency [[anemia]]
* Treatment of [[vitamin B12 deficiency]]
* Rebound effect after [[thrombocytopenia]] treatment
* Metastatic cancer
* [[Lymphoma]]
* Rheumatologic disorders
* [[IBD]]	
* Celiac disease	
* [[Kawasaki disease]]	
* [[Nephrotic syndrome]]	
* POEMS syndrome	
* Thermal [[burn]]
* [[MI]]
* Severe [[trauma]]	
* [[Acute pancreatitis]]
* Post-surgery, especially [[splenectomy]]
* CABG	
* [[TB]]
* Acute [[bacterial disease|bacterial]]/[[viruses|viral]] infections	
* [[asplenic patient|Asplenia]]	
* [[Allergic reaction]]
* Medication reactions: vincristine, [[epinephrine]], [[glucocorticoids]], IL-1B, ATRA, thrombopoietin, [[LMWH]]<ref>uptodate</ref>

===Autonomous thrombocytosis===
* [[Essential thrombocytosis]]
* [[Polycythemia vera]]
* Mixed [[myelodysplastic syndrome|myelodysplastic]] and/or [[myeloproliferative disorders|myeloproliferative syndrome]]

===Spurious (false) thrombocytosis===
* Mixed cryoglobulinemia	
* Cytoplasmic fragments	
* [[Bacteremia]]

==Evaluation==
===Workup===
*CBC
*Chem 7
*ESR
*Bone marrow biopsy sometimes needed

===Evaluation<ref>Tefferi, A, et al. The 2008 World Health Organization classification system for myeloproliferative neoplasms: order out of chaos. Cancer. 2009; 115(17):3842-7,</ref>===
Per the WHO guidelines, diagnosis of ET requires all of the following:

{| class="wikitable"
|-
! Major criteria
|-
| Thrombocytosis ≥ 450 x 10<sup>9</sup>L
|-
| Megakaryocyte proliferation with little to no granulocyte or erythroid proliferation
|-
| Not meeting criteria for CML, PV, PMF, MDS or other myeloid neoplasm
|-
| No evidence of reactive thrombocytosis or presence of JAK2V617F or other clonal marker
|}

==Management==
*[[ASA]] 81mg
*Myelosuppressive agents ([[hydroxyurea]], Interferon-α)
*Anagrelide

==Disposition==

==Also See==

==References==
<references/>

[[Category:Heme/Onc]]