Hello @markbrinkley and welcome to Mayo Connect.
I'd like to invite @tomewilson to this discussion as his wife has been treated at Mayo for NETs as well. Perhaps he can give you some more information. I am pleased to know that you will be seen at Mayo, they have a great team there.
I have had surgeries for three NETs in the duodenal bulb, so I can understand, just a little, how concerning this can be.
If you care to share more, I would be interested in knowing what kind of symptoms you had that led to this diagnosis. Also, what types of diagnostic tests were used? (I'm assuming an upper endoscopy and biopsy was part of the diagnostic procedure.) Do you have any carcinoid syndrome symptoms, like diarrhea, flushing, etc.?