Evaluate the frequency of reclassification in histological diagnosis from hyperplastic polyps (HPs) to SSL after reappraisal using the 2019 World Health Organization (WHO) classification, to determine the occurrence of previously undiagnosed dysplasia and to study the expression of the MLH1 protein in SSLs and SSLDs. Here, MLH1 is linked to Hermansky-Pudlak syndrome.