This ASG video tip is sponsored by Braintree, maker of the newly approved Soufflave and Soutab. The seriated class of colorectal polyps includes the sessile seriated polyps, the traditional seriated adenomas, and the hyperplastic polyps. Hyperplastic polyps are not considered precancerous and traditional seriated adenomas are relatively rare left-sided lesions that are precancerous, but because they're infrequent compared to the sessile seriated polyps, the sessile seriated polyps are the major group of precancerous lesions within the seriated class. This slide shows the progression of sessile seriated polyps to cancer. The initial lesion and perhaps 95% of all sessile seriated polyps are the sessile seriated polyp or adenoma without cytological dysplasia. Now I first want to point out that sessile seriated polyp and sessile seriated adenoma are in fact synonymous terms, virtually synonymous, and often sessile seriated polyp is now preferred because this lesion usually has no dysplasia in it, and endoscopists are used to thinking of the conventional adenomas where the term adenoma implies dysplasia in every case, and these lesions aren't dysplastic, so use of the term sessile seriated adenoma can confer some confusion. So that is the initial step. The next step in the progression is the sessile seriated polyp with cytological dysplasia, and that is therefore a more advanced lesion, and then the final step is seriated cancer, and what's often not recognized is that these stages can frequently be seen endoscopically, and therefore by endoscopic criteria you can estimate the importance of the lesion that may guide endoscopic, or in the case of cancer, surgical resection, as well as guiding expectations regarding histologic and molecular evaluation of the lesion. So here is the initial lesion in the sessile seriated polyp to cancer sequence. This is the sessile seriated polyp without cytological dysplasia. This lesion has nice type 1 features, but in addition it demonstrates several of the features that are typical of sessile seriated polyps as opposed to hyperplastic polyps. First of all, it has some black open pits, large open pits that are typical. The edges are indiscreet as demonstrated by the red arrows on the right. There are these parallel white lines, the so-called cloud-like appearance designated by the black arrows at the bottom, and typical of nice type 1 features, there are very few blood vessels. The yellow arrows point to the only blood vessels that are visible on the surface. There are no features on the surface of this polyp to suggest that it has dysplasia. So this is the initial lesion in the sequence, the sessile seriated polyp without cytological dysplasia. Those features of the sessile seriated polyp are very distinct from the typical features of a conventional adenoma. Here's a large conventional adenoma which is covered in blood vessels. The red structures are vessels. The pits are white. They are long and tubular, very distinct from the sessile seriated polyp. The second step in the sessile seriated polyp to cancer sequence is the sessile seriated polyp with cytological dysplasia, which combines the features of the SSP with a conventional adenoma. Most of this lesion is SSP, but over on the right edge we see a small five millimeter area with typical features of a conventional adenoma. Very dense in blood vessels, tubular pits. This is the dysplastic portion of the SSP with cytological dysplasia. This still photograph from the previous case shows the dysplastic portion of this SSP with cytological dysplasia delineated in yellow inside that yellow circle. The final step in the progression of sessile seriated polyp to cancer is demonstrated in this video. This is a sessile seriated polyp that has given rise to cancer. How can we tell that this cancer arose from an SSP and not from a conventional adenoma? Well we can see the residual SSP off to the left. The right side of the lesion which is ulcerated is a typical small cancer and when we look at it in NBI we can see that the vascular pattern there is completely disrupted. It actually has nice type 3 features, but the way we can tell that this cancer arose from an SSP is by looking off to the left and seeing that the residual benign polyp is not typical of an adenoma but rather of an SSP. There are no blood vessels, there are large open pits, so this is what we're trying to prevent by effectively removing SSPs, the progression to cancer. In the still photograph from this case we can see the residual SSP to the left of the black line, no areas of cytological dysplasia, very few blood vessels, the large open black pits typical SSP without cytological dysplasia, but to the right of the line there is ulceration, the area marked by the yellow areas. This is cancer and it's cancer that is at least invasive into the deep submucosa. So in these videos and photographs we've seen a nice demonstration of how we can endoscopically recognize the different stages of the sessile serrated polyp to cancer sequence. The SSP without cytological dysplasia, then the SSP with cytological dysplasia, and finally the SSP in which cancer has arisen. I think it's very valuable to remain cognizant of this sequence as we search carefully for serrated lesions and we attempt to interrupt and prevent this progression to cancer. you

colorectal polyps

sessile serrated polyps

precancerous lesions

endoscopic examination

colorectal cancer