If you have a pituitary tumor and high gastrin levels but an octreoscan came back negative, what is likely wrong?

There is a condition: Called men (multiple endocrine neoplasia) that can be associated with pituitary tumors, gastrin producing tumors (and other tumors of the pancreas) and parathyroid tumors. It is caused by a certain gene mutation. Things to consider-1. If you are on a proton pump inhibitor, that can raise your gastrin level. 2. Octreotide scans are not the most sensitive imaging technique, and may miss some tumors.

Consult a good Endoc: A good endocrinologist can guide you further. I hope you do not have men syndrome where such a combination of endocrine disorders can occur. Octreo scan only picks up bigger tumors.... So you can have small gastrin making tumors which may not show up on the scan. But serial gastrin blood levels will help to know what you are dealing with. But have your endocrine specilaist help you sort it out bet.