If I may: As a longtime copy editor and fact-checker, I urge you ***never*** to use Wikipedia -- never. Ever.

Anyone can enter anything -- literally (I have some appalling screenshots, which I'll share) -- and there is NO editorial process through which anyone trained or knowledgeable checks the material for accuracy. In addition, there is no editorial board to ensure that all articles are written for layperson consumption, so some are a real slog.

I googled for Mayo + ctDNA; didn't get a hit for Mayo -- which shares, for free, an ENORMOUS amount of accurate info -- but here are links from Anderson and Dana-Farber. Also, Healthline is a good source for dr.-generated content for laypersons (my state's official library led me there), as is Hopkins.

(@sofee2022, I think these will be of use. Also, to the best of my knowledge only your doctor can tell you whether to be concerned about a cyst on your pancreas. If you have one, then presumably your dr. did the diagnosis -- ? If you're asking bc someone you care about has one, then perhaps ask that person to be forthcoming.)
https://www.mdanderson.org/cancerwise/liquid-biopsies--understanding-ctdna-and-circulating-tumor-cells.h00-159463212.html
https://blog.dana-farber.org/insight/2023/06/what-is-ctdna-and-do-i-need-mine-tested/