[heblaj01]

Karen,
If,as you tell, your onc is not sure if it is a tumor or a cyst in or near the pancreas, then this is one more reason to have a PET/CT scan which will determine if it is malignant or not. The difference is important since a cyst is not malignant & is usually ignored unless it is growing quickly which not the case in most instances.
Since this is a single spot in the CT scan of the pancreas, should the PET/CT scan turn out to be positive (malignant), I would ask in advance a second PT/CT scan a hour or so after the first one to eliminate the possibility of a false positive. The second scan is compared to the first one & if it does not show an increase in the image uptake, then it is a false positive.(If it is a false positive, the second scan should actually show a decrease of the uptake which is a number usually between 0 & 7, called SUV. The smaller the number, the better).

I think a PET/CT scan provides more info than a CT scan & reduces the number of possible false positives.
Even if the results of the PET/CT scan,whatever they are, do not make a difference in the choice of the treatment your onc has already selected, you will at least feel relieved of a mental burden if they show it is a cyst.