Serrated polyps of the colon and rectum: Remove or not?

Figure 1 Example of hyperplastic polyps. A: White light endoscopic view. A slightly discolored, flat elevated lesion measuring 3 mm in size was detected in the sigmoid colon; B: Narrow-band imaging endoscopic view. The lesion was detected as a whitish lesion without expanded, brown meshed capillary vessels, which are seen in conventional adenomas; C: Chromoendoscopic view. Kudo type II asteroid pits were identified on the lesion surface.

Figure 2 Endoscopic features of sessile serrated lesions. A: Mucous cap (white light endoscopy); B: Red cap sign [narrow-band imaging (NBI) endoscopy]; C: Cloud-like surface (white light or NBI endoscopy); D: Dilated and branching vessels (NBI endoscopy); E: Expanded crypt openings (NBI endoscopy); F: Type II open-shape pits (chromoendoscopy).

Figure 3 Endoscopic features of sessile serrated lesion with dysplasia. A: Small nodule on the lesion surface (arrow); B: Small nodule on the lesion surface (arrow); C: Large nodule on the lesion surface (arrow); D: Partial protrusion of the lesion (arrow).

Figure 4 Endoscopic features of traditional serrated adenoma. A: White light endoscopic view; B: White light endoscopic view; C: Narrow-band imaging endoscopic view exhibiting “leaf vein-like” expanded, brown capillary vessels; D: Chromoendoscopic view exhibiting type IV_H pits.

Figure 5 Histopathological features of colorectal serrated polyp. A: Microscopic view of hyperplastic polyp; B: Microscopic view of sessile serrated lesion (SSL); C: Microscopic view of SSL with dysplasia (SSLD) (conventional adenoma-like dysplasia); D: Microscopic view of SSLD (serrated dysplasia); E: Microscopic view of SSLD (“cryptal dysplasia”); F: Microscopic view of traditional serrated adenoma exhibiting papillary growth; G: Microscopic view of traditional serrated adenoma.

Figure 6 Proposal of treatment algorithm for colorectal polyps. NBI: Narrow-band imaging; NICE: Narrow-band imaging international colorectal endoscopic; JNET: Japan narrow-band imaging expert team; HP: hyperplastic polyp; SSL: Sessile serrated lesion; SSLD: Sessile serrated lesion with dysplasia; TSA: Traditional serrated adenoma.