Thank you so much for responding to my question!! I have alot of questions for the dr. making a list!
Yes, it can be related to a pituitary tumor - DHEA is higher in those that have Cushing's disease. Ironically, Cushing's disease (pituitary source) can also cause adrenal lesions, so even if they find something on the adrenals, they won't know if it is due to the Cushing's or something else.
Another thing to consider is that myself and many of my Cushing's buddies who had our adrenals removed had normal scans before surgery even though all our adrenals were very abnormal as well, even after surgery, the CTs showed we had normal adrenals (how sad!) so imaging of the adrenals is not perfect. This happened to so many of us and in different countries and states - so if you get a normal scan... take it with a grain of salt.
So make sure you get to a pituitary expert, get copies of everything and read up so you know what is going on.