As ET is a chronic blood disorder then, in theory, it never goes away. So if Platelet counts return to the normal range without medication, then it suggests a possible mis-diagnosis.

If it was a Reactive Thrombocytosis, and the root cause was no longer there, then that would explain it. Of course, there's no way to confirm that now.

Alternatively, there is a theory that ET is a cyclic thing which goes into a natural decline after it has peaked. But, as far as I am aware, there is no research being done on this.

As far as drugs go, P-32 (a radio active injection) is available, which is supposed to reduce levels for several months - Could it be possible that this has been used, and has had a longer term effect?
Mark J.