Is essential thrombocythemia a form of cancer?

Neoplasm. Essential thrombocythemia (et) is part of group of myeloproliferative neoplasm (mpn) - is a clonal disorder. Mpns are predisposed to clonal evolution and disease transformation to myelodysplasia and/or acute leukemia. The propensity to transform into acute myeloid leukemia differs among the subgroups- being the highest for cml- greater than 90% if left untreated and et being the least - about 5%.