Let's say you have a mass at the head of the pancreas that is incidentally detected on a scan. Let's further stipulate that the mass does not have anything that clearly indicates that it's pancreatic cancer - but also does not have signs of being a benign cyst. What do you do about it?

Well, you can do nothing, and just follow it up with repeat scans. Or you can go to surgery. Both cost money and time. But if you have pancreatic cancer, aggressive resection is essentially the only chance of a cure. So both patients and doctors are highly incentivized to go straight to surgery. If it turns out, once the mass has been resected, that it's actually a completely benign tumor, was the procedure really "unnecessary"? Because taking a piece of it and looking at it under a microscope is the only way you'll ever know for sure.

Would you like to try live your life normally with that sword of Damocles hanging over your head? I wouldn't.