ABSTRACT
Objective To investigate the morphological features of colorectal sessile serrated adenoma/polyp (SSA/P) by white light endoscopy (WLE) and narrow band imaging (NBI). Methods A retrospective analysis was made on the morphological characteristics of SSA/P from January 2014 to March 2017, and compared with HP. Results There were 50 cases of SSA/P from 41 patients and 50 cases of HP from 43 patients. SSA/P located in the right colon was more than HP, but the difference was no statistical significance (16 cases vs 14 cases,P > 0.05). SSA/P have 11 cases of Type Is, 21 cases of Type IIa, 16 cases of Type IIb, 2 cases of Type LST, HP have 17 cases of Type Is, 25 cases of Type IIa, 8 cases of Type IIb, there was no significant difference (P > 0.05); SSA/P has more mucus than HP (37 cases vs 11 cases, P < 0.05). In NBI: The proportion of SSA/P with a red mucus cap, indistinctive borders, irregular shape, black dots inside the crypts, Cloud-like surface, Type II-O pit pattern and varicose microvascular vessels were higher than that of HP (P < 0.05). In the differential prediction of SSA/P and HP: Black dots inside the crypts (OR
ABSTRACT
Hyperplastic or serrated polyps were once believed to have little to no clinical significance. A subset of these polyps are now considered to be precursors to colorectal cancers (CRC) in the serrated pathway that may account for at least 15% of all tumors. The serrated pathway is distinct from the two other CRC pathways and involves an epigenetic hypermethylation mechanism of CpG islands within promoter regions of tumor suppressor genes. This process results in the formation of CpG island methylator phenotype tumors. Serrated polyps are divided into hyperplastic polyps, sessile serrated adenomas/polyps (SSA/Ps), and traditional serrated adenomas (TSAs). The SSA/P and the TSA have the potential for dysplasia and subsequent malignant transformation. The SSA/Ps are more common and are more likely to be flat than TSAs. Their flat morphology may make them difficult to detect and thus explain the variation in detection rates among endoscopists. Challenges for endoscopists also include the difficulty in pathological interpretation as well surveillance of these lesions. Furthermore, serrated polyps may be inadequately resected by endoscopists. Thus, it is not surprising that the serrated pathway has been linked with interval cancers. This review will provide the physician or clinician with the knowledge to manage patients with serrated polyps.