Does a serotonin level of 583 ng/mL suggest carcinoid tumor?

Hello doctor,

My 5 years old son's serotonin level is 583 ng/mL, and the normal range is 50 to 200 ng/mL. So, we did chromogranin A blood test. It was 16, which is slightly elevated, as the normal range is 1.9 to 15. Should we be concerned and see a specialist? Please advise. Thank you.

Hi doctor,

Thank you so much. So you are saying, high serotonin and elevated chromogranin A are not necessarily an indication of a tumor? What can affect the levels? We did a fasting test. We have not done any radiology tests yet, just this blood work. Remaining blood work is normal. The child is 5 years and there are really no other symptoms. I just did research and it seems that combination of high serotonin and CgA can indicate cancer. So, I am very concerned. Do I need to be concerned?

Hi doctor,

Thank you so much for such an amazing response. My son has mild autism, and levels of neurotransmitters, serotonin, in particular, were recommended to be done in his case. That was the original reason why we did serotonin test. And only when it came three times higher, we decided to do CgA just to rule out carcinoid, as it often comes high in cancer patients, I was told. CgA is only very slightly elevated, so I do certainly hope that it was perhaps the food that he ate the day before or something. We are going to make an appointment with a pediatric endocrinologist just to be safe. Our primary care physician also does not think that my son has carcinoid, but we all would like to be on a safe side. I really appreciate your response. I will ask the doctor if we can perform 5-HIAA urine test. It seemed that 5-HIAA only comes back positive in advanced stages of carcinoids, and it is not a good marker for beginner stages. Do you agree?