Essential Thrombocythemia
Supplemental Studies
- 40-50% JAK2V617F mutations
- 1% MPL W515K/L
- Cytogenetic abnormalities in 5-10% of cases
- +8, +9q, del(20q)
- Absence of Ph’ or BCR-ABL1
- Rare p230 isoform can present with thrombocytosis
| Disorder | Molecular or Cytogenetic Alteration | Test Used |
|---|---|---|
| Chronic myelogenous leukemia | BCR-ABL1 | CG, PCR |
| Polycythemia vera | JAK2 V617F, JAK2 exon 12 | PCR |
| Essential thrombocythemia | JAK2 V617F, MPL W515K/L | PCR |
| Primary myelofibrosis | JAK2 V617F, MPL W515K/L | PCR |
| Hematolymphoid neoplasms with FIP1L1-PDGFRA | FIP1L1-PDGFRA | CG, FISH with CH1C2 probe |
| Hematolymphoid neoplasms with eosinophilia | ETV6-PDGFRB. various involving FGFR1 | CG |
| Chronic eosinophilic leukemia NOS | none specific, may have clonal CG abnormalities | CG |
| Mastocytosis | KIT D816V | CG, PCR on BM, not PB |
| Acute myelogenous leukemia, even if <20% blasts | inv or t(16)(p13.1q22); CBFB-MYH11 | FISH |
