Is it possible for a body to absorb a cyst suddenly without a trace thats been there for quite awhile? it was removed once before, but returned and was there for two years until a couple of days ago.

Yes w/ ganglion cyst: Yes a ganglion cyst on the back of the wrist can be there for many years and disappear overnight.

Dont' ignore cysts: I take it you are talking about breast cysts. The answer is yes, cysts can absorb - but do not ignore a mass in your breast for two years. If a mass persists after two or at the most, three menstrual cycles, have a doctor look at it and at least, do a needle biospy to make sure it's not cancer.