Hello @rebecka93

I appreciate your comment and questions. To answer your questions:
No, I never had any symptoms, the NETs were found during a routine upper endoscopy for other digestive issues, which was 20 years ago.

It is felt that these NETs were primary and that the previous surgeries might have left some cells in the area (all the NETs were found in the same location).
My other lab tests (Serotonin blood levels, 24-hour-urine) do not indicate any carcinoid activity and I have no carcinoid syndrome symptoms. I'm nearing age 75 and have chosen not to go through additional testing unless new symptoms or problems appear.

Given your son's age and previous digestive tract problems, I hope that he is able to see a NET specialist. Here is another link to lab tests that are used for diagnosis and follow up which might be helpful to him. This is from the CCF website as well:
--Diagnosis and follow up
https://www.carcinoid.org/for-patients/diagnosis/diagnosis-and-follow-up-tests/
I hope that all goes well for your son. Will you post if you have other questions?