scars on the ASGE SuTab tip of the week. Here's an adenoma recurrence seen first in white light and then in MBI. Identifying recurrences on EMR scars is going to require a pit pattern analysis. And just as when we looked at the previous EMR report to help determine the location of the scar, so we want to look at the previous pathology report to determine if the lesion was adenomatous or serrated, because we're going to be looking for different types of pits, depending on the original histology of the lesion. And I have occasionally in biopsy EMR scars after removing an adenoma, gotten a report back of hyperplastic polyp. And I don't know what that means. I usually ignore it. I suppose if it came back as sessile serrated lesion, which I can't recall happening, I would go to the pathologist and try to figure out what's going on. But we expect the recurrence to be of the same histology, obviously, as the original lesion. A few things worth noticing here. First, there are a couple of mounds of CLIP artifact, type three, completely mature, non-inflamed CLIP artifact designated by the yellow arrows. And the pits that are on this type three CLIP artifact, non-inflamed CLIP artifact, are the normal tiny white pits of colonic mucosa. They're identical to this normal fold that's seen in the upper left of the image and marked with the red arrows. It's also worth noting again that the pits within the scar, and you can see part of the scar below the white line, are uniform in size and spacing, but they're somewhat different than the normal pits in that they're a bit bigger. And again, we're gonna see variable patterns depending on the phase of healing, the amount of inflammation in the base of the scar that are somewhat different from normal, but don't represent neoplasia. And then finally, of course, is the recurrence itself, which is now designated within this purple line. And we apply our pit pattern analysis. We can see that this has nice two features, CUDO 3L, maybe some CUDO 4 if you prefer, CUDO. But basically in NBI, it is brown in color, more brown than the surrounding tissue. That brown is the result of blood vessels. All of the brown lines within that purple circle are blood vessels. They are surrounding white structures that are long and tubular. This is obviously nice two or CUDO 3L. So this is the recurrence and it's the target. Couple of things that are important here. First of all, we're examining in NBI because NBI gives us, I think, clearer definition of the pits and clearly of the blood vessels. And we've got the near focus on. We're using magnification along with our high definition scope to get the best evaluation of the pits that we can. And the other thing is important, I think, is not so much that just recognition of the adenoma recurrence, but recognition of what is not recurrence, recognition that there's clip artifact there that doesn't need to be removed. The target for our treatment is that area within that purple circle. Here's a scar in the ascending colon. And looking at this without magnification and white light, no obvious problem, but you start to see as we get into near focus and then into NBI that there's recurrence. The yellow arrows here designate some polyploid folds that have perfectly normal pit patterns on them. So that is type three clip artifact resulting from the original EMR and clip placement. On the other hand, this area that's within the white line, that is browner in color. It has blood vessels that are thicker. There's variability in the pit shape. There are some tubular pits in there. That's the nice two pattern that is residual adenoma. And another thing that I think we tend to pick up subconsciously when we see recurrences, and you'll notice this if you look back at the first case that we presented, is that the margins are distinct. You can tell where the margin is everywhere. It's another characteristic of adenomas in general, including recurrent or residual adenoma on EMR scars. This is a referral of an interesting type that I get sometimes where the doctor says, I removed the polyp completely, I think, but I would like you to do the follow-up, which may reflect some lack of confidence that it was completely resected. I tend to distinguish the situation a bit from a polyp that was partly removed and the referring doctor knows that they didn't get it all. So in this case, we're looking at the scar and we're looking at it less than two months after the resection. So the pits in the base of the scar have a little bit of a different look. There are a couple of areas here that are of concern. We've put some injection fluid in on the distal edge and then we're going back to the top end, looking at it in MBI. First, we have scattered nodules of mucosal distortion. That's type three non-inflamed clip artifact. We can recognize that. That's not a problem. We leave that alone. Right in the scar, using white light and near focus, we see two red flat areas that are worrisome for residual adenoma. This is confirmed later with MBI and near focus after we've already removed a third area of residual lesion off to the left side of the scar. So these arrows are on discrete nodules. You can see that both of them have discrete borders and both of them have nice two pit patterns. This is the left-hand edge of the scar and there's an area of concern. Looks a little bit red in white light surrounded by the black line. Notice also the texture difference in the scar itself at this stage. Less than two months of follow-up compared to most of the scars that we have seen, which have been at six months of follow-up. So the yellow arrows are pointing to that. Looks very different at this point in time. And again, I point out that recognizing that the scar itself at different phases of healing has a texture change, a pit pattern that's different than normal, but also different than neoplastic change. That same area at the left-hand edge of the scar with the residual adenoma outlined in white, you can see that that area has a discrete border. It's slightly elevated, has a nice two pit pattern. And it's distinct from the scar itself marked with the yellow arrow where we see uniform size pits that are larger than the normal pits, the normal pits being shown here by the red arrow. So we have inflammatory type pits really still in the base of the scar. And when we're evaluating these EMR scars, we need to be able to distinguish the non-neoplastic changes, which could be normal in the case of type 3 CLIP artifact, could be inflammatory with type 1 or 2 or in the base of the scar, and distinguish both of those from the neoplastic changes, the residual adenoma that we need to treat. Following up SSLs, first we're looking for a different type of pit. And now in close focus in MBI, you can see a three millimeter recurrence with the nice type 1 pattern, no blood vessels, uniform shaped dark pits. So in a second, we'll see the larger scar again, SSL recurrence. Here's another SSL recurrence, large flat scar, no CLIP artifact, because no CLIP's used to close the cold EMR at the upper edge, two tiny little spots of residual SSL. Here we see arrows on these two tiny areas of SSL recurrence and this emphasizes the importance of inspecting the entire EMR scar very carefully because of course we want to identify every visible recurrence and treat it endoscopically at the time of follow-up. So use electronic chromoendoscopy, use magnification when available and inspect the entire scar carefully. Use these skills of pit pattern analysis to distinguish the pits of either SSL or adenoma, both of which are neoplastic and need resection from the changes sometimes seen in the base of the scar and the changes of CLIP artifact. Next week, treatment of EMR recurrences on the ASGE SuTab tip of the week.

recurrences

EMR scars

pit pattern analysis

pathology reports

clip artifacts