Is essential thrombocythemia a type of blood cancer?

High Platelet count: Essential thrombocythemia is a hyperproliferative disorder characterized by elevated platelet counts. The problem is due to abnormal signalling in a "stem cell" leading to uncontrolled proliferation of platelets. Technically it is now considered a neoplasm but with a benign behavior for the most part. About 3-4% of cases transform into an acute leukemia towards the latter stages of its course.

Sort of: It is an abnormal state and is similar to blood cancer.