ET stands for Essential Thrombocytosis. , I have this also and with a JAK2 mutation.
If I understand it correctly it is a form of blood cancer it makes your platlets over produce which can lead to a possible diagnosis of leukemia.
I take a drug called hydrea and it has decreased by platlets form 700000 to 380000.
I also get confused becaused according to my doctor its a fine line between ET and Leukemia.