Table 2

Comparison of histopathological classifications

Morphology of duodenal mucosal biopsy	Classification
Morphology of duodenal mucosal biopsy	Marsh^* 7	Marsh-Oberhuber16	Corazza10
Normal	Type 0	Type 0	Normal
Normal architecture and increased intraepithelial lymphocytes ≥25/100 enterocytes	Type 0	Type 0	Grade A
Normal architecture and increased intraepithelial lymphocytes ≥40/100 enterocytes	Type 1	Type 1	Grade A
Normal architecture and increased intraepithelial lymphocytes ≥40/100 enterocytes with crypt hyperplasia	Type 2	Type 2	Grade A
Partial villous atrophy and increased intraepithelial lymphocytes ≥40/≥25/100 enterocytes	Type 2 hyperplastic lesion Crypt hyperplasia, increased crypt height and influx of inflammatory cells	Type 3 destructive	Grade B1 atrophic, villous to crypt ratio is <3:1
		Type 3a partial villous atrophy; villi blunt and shortened with a villous:crypt ratio, 1:1
		Type 3b subtotal villous atrophy; villi atrophic but still separate and recognisable
Total villous atrophy intraepithelial lymphocytes ≥40/≥25/100 enterocytes	Type 3 destructive severe inflammation, flat villi; hyperplastic crypts	Type 3c total villous atrophy; villi rudimentary or absent; mucosa resembles colonic mucosa	Grade B2 atrophic, villi are no longer detectable
Atrophic hypoplastic lesion: flat mucosa, normal crypt height, no inflammation with normal intraepithelial lymphocyte counts	No equivalent	Type 4	No equivalent

↵* Marsh initially explored the association of mucosal damage with a progressively increased gluten intake in treated patients with celiac disease. This staging has since been used as a classification.