Curriculum · Hematology
Myeloproliferative neoplasms: comparison
What it is
The myeloproliferative neoplasms (MPN) are compared as four: CML, PV, ET and PMF. There is no dysplasia in them. Myelofibrosis, written MF, is one of them, and its name is the one that returns in the marrow and film findings below.
Causes and risk
The genetics separate them:
- CML: Philadelphia chromosome, t(9;22), BCR-ABL1
- PV: JAK2 mutation in 95% of the cases, an exon 2 mutation
- ET: JAK2 mutation 50%, CALR mutation 30%, MPL mutation 3%
- PMF: JAK2 mutation 50%, CALR mutation 25%, MPL mutation 8%
In short, PV, ET and myelofibrosis carry JAK2, while CML carries the Philadelphia chromosome.
How it presents
Splenomegaly is +++ in CML and PMF, and only + in PV and ET. Marrow fibrosis runs the other way: it is +++ in PMF and only +/- in CML, PV and ET.