This is a serrated polyp; in particular, it is a sessile serrated polyp, or, as we now prefer to call it, a sessile serrated lesion (SSL). SSLs are potentially premalignant polyps that can be found in up to 11% of screening colonoscopies. They are not like an adenoma, which is pink and discrete, with an altered crypt pattern. The mucus covering the SSL is stained by bile, which gives it a yellowish hue. A mucus coat is characteristic of SSL, although it is not pathognomic. About 50% of SSLs are covered in mucus, and this is rare in polyps of other histologies. Without their mucus coat, SSLs are flattish, pale, and can be hard to detect.