How to "pick up" colorectal serrated lesions and polyps in daily histopathology practice: From terminologies to diagnostic pitfalls

Table 1 Major classifications of dysplasia patterns with MLH1 status

Cenaj et al[23]		Liu et al[24]		ASCP (2021)[25]		WHO (2019)[6]
Categories of dysplasia	MLH1 loss (%)	Categories of dysplasia	MLH1 loss (%)	Categories of dysplasia	MLH1 loss (%)	Categories of dysplasia	MLH1 loss (%)
Intestinal dysplasia: Low-grade; High-grade	NA	Adenomatous dysplasia	5	SSLDad1	6.1	NA1	NA2
Serrated dysplasia: Low-grade; High-grade	NA	Serrated dysplasia	13	SSLDser	59.1
Mixture of a serrated and intestinal dysplasia: Low-grade; High-grade	NA	Dysplasia NOS	83	SSLDnos SSLDad2	35 24.3
		Minimal deviation dysplasia	91	SSLDmin	50

¹Classification of dysplastic morphology in sessile serrated lesions with dysplasia is not recommended.

²MLH1 can be used in cases of minimal dysplasia.

ASCP: American Society of Clinical Pathology; WHO: World Health Organization; SSLD: Sessile serrated lesions with dysplasia; NOS: Not specified; SSLDad1: SSLD “Adenomatous type 1”; SSLDser: SSL, “Serrated type”; SSLDnos: SSLD, “Not otherwise specified”; SSLDad2: SSLD, “Adenomatous type 2”; SSLDmin: SSLD, “Minimal Deviation” type; NA: Not available.