@pokeymama: a 24hour urine test is beneficial in NET diagnosis.
Gallium or Copper Dotatate PET scan is a gold standard test. Contrast Evoist MRI best visualizes NET size in Liver. These tests result if given at a cancer hospital with NET specialists and radiologists familiar with NET tumors successfully. You are not guaranteed a diagnosis but I believe that it is the best option. Some NET patients have never found their Primary Tumor, but this fact has not delayed their successful treatment.
You are not alone in not finding the tumor to biopsy - NET tumors can be very illusive. Mine was found surprisingly by Gastroenterologist performing a Endoscopy and saw a bit of something behind the Duodenum. A biopsy was taken & diagnosis made… then was sent for 2nd opinion with results of NET (carcinoid tumor disease). The Pathologist provided needed Grade, Stage, as well as staining slide to provide other valuable data to determine best treatment decisions. You deserve answers, but you need the best NET specialists on your case. Now is the time to do whatever you have to do to get the best care money can buy!
I would learn everything about your type of cancer and stay informed by asking questions from many NET organizations you will find online. If you ask for help - you will be offered peer experiences, treatment details and information that will help you make medical decisions. Be persistent until you get the info you want. No question is unheeded.
Best to you… Bette (dbamos1945)