So looking at some type 1 lesions then, what do they look like? So here's the typical hyperplastic polyp, and you'll notice the little black dots. Those are the pits. The pits of most hyperplastic polyps are dark as opposed to light, but they can be either. And nothing on the surface of this lesion is a blood vessel. There are no visible vessels, at least in this magnification. Here we can see a couple of blood vessels in the lower left. But for the most part, what we have here is a pattern of black dots. And very importantly, the black dots are nearly uniform in size. So it's the uniformity of the pits and the fact that these blood vessels are very thin. You can sort of see them in the lower left part, just around a few pits. But this is a very high confidence type 1 lesion, probably hyperplastic. This is also hyperplastic. You see more dark spots, but those dark spots are actually pits. We'll come back to these large open pits here. This is a fairly small lesion to be seeing a lot of open pits, a few lacy blood vessels in the lower left. This is also a serrated class lesion type 1. Now this is actually, I think, a confusing lesion and one that could reasonably be called low confidence. But especially if you look in the lower right, you'll see that the pits are almost entirely uniform in size. Part of the trouble is that there are parts of this where some of the pits appear to be quite long. But over the most part, the pits are quite uniform in size. They also, in many cases, have a little central dot in the middle of them. And that little tiny central dot is typically not seen within the pits of adenomas. Now here is a hyperplastic lesion in which the pits actually, for the most part, look white. They have a little white centers in them, a little bit different, but still a high confidence type 1 lesion, hyperplastic. Here's another one, some a little bit darker pits in the middle, very typical hyperplastic. And here's a slightly bigger lesion. You can see off to the left a few large open pits. These are the large open pits that we'll come back to that suggest sessile serrated lesion. And here's another such typical hyperplastic, really no vessels. This one has lacy vessels on it and also has this bumpy appearance that's often referred to as the cloud-like appearance, which is characteristic of sessile serrated lesions. But these are lacy vessels with a little bit more magnification. You can see that those are just coursing around pits. They actually are sort of an interconnected lace work, but in some areas they're slightly more prominent and you can see them from a little distance.

lesions

endoscopy

hyperplastic polyps

serrated class polyps

pits