Polycythemia Vera

Supplemental Studies

>99% JAK2V617F or exon 12 mutations
- Found in all myeloid lineages
- May also be found in Essential Thrombocythemia and Primary Myelofibrosis (50% of cases)
  - Also more rarely in a variety of other myeloid neoplasms (see DDX in left sidebar)
Erythropoietin level should be low
Absence of Ph’ or BCR-ABL1 negative if clinically indicated
Karyotypic abnormalities (+8,+9/del(9p), del(13q), del (20q))
- In 20% of cases at diagnosis
- In 80-90% of post-PV myelofibrosis

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

PCR = polymerase chain reaction, CG = conventional cytogenetics, FISH = fluorescent in situ hybridization