Those are really sweet numbers! Well within normal range for both tests. That said, I wouldn't turn down an EUS and biopsy just to be sure that the cyst is benign. Tumor marker tests are unreliable as diagnostic tools, absent other symptoms, although they're useful for tracking treatment progress. You didn't say whether there were other symptoms, but if it were me, I'd pursue additional eval given what you've described.

As far as symptoms, I've had lower back problems for several years, oftentimes shooting pains up my back, which happened about a year and a half ago. I started feeling like something was rubbing up against something under my left ribs and found it difficult to stand up straight. The orthopedic doctor sent me for physical therapy. The therapist said I had lost a lot of strength in my core because of the shooting pains in my low back. I continued to have the discomfort, I wouldn't call it pain, for several months. In March of last year I had a rib x-ray, MRI, and ultrasound and no mention of a cyst. My PCP said if it gets worse, go to the emergency room. Since then it occasionally got better, but never went completely away. About 2 months ago I started having a tight feeing right under my ribs as if I had a belt right there squeezing. No pain, just discomfort. Now I can't eat much because I feel full all the time. No nausea or gastrointestinal problems. Went to a gastroenterologist who did bloodwork. Hepatic tests, which were within normal range, and the CEA and CA19-9. He also did an MRCP/MRI which showed two cysts, one the radiologist more or less said keep an eye on it with regular MRIs, and the 2 cm cyst which he suggested the EUS. Now the gastroenterologist is going to schedule that.

Hello @caroline24 and welcome to Mayo Connect. I've read your posts and certainly understand your concerns. Any problem with the pancreas always brings worries. I had cysts show up on my pancreas about 15 years ago. I also had a EUS (but no biopsy as it appeared to be benign). I've had follow-up MRIs on a regular basis since then with no changes in size or the number of cysts. They have basically remained the same.

Like you, I was quite worried at the start, but now accepting it as not a great of a threat to my health (or happiness). Perhaps you could ask your GI doctor to do pancreatic blood work. This would show if there are any problems with the functioning of the pancreas.

Here is another discussion on Connect that might help you to understand this better,
https://connect.mayoclinic.org/discussion/cyst-on-pancreas/
Cyst on Pancreas? | Mayo Clinic Connect

Please continue to post about your questions and concerns. Waiting for the EUS and the results can be stressful.