Table 1.

Marsh classification of histologic findings in celiac disease

Marsh 0	Normal mucosal architecture without significant intraepithelial lymphocytic infiltration.
Marsh I	Lymphocytic enteritis: Normal mucosal architecture with a marked infiltration of villous epithelium by lymphocytes; arbitrarily defined marked as more than 30 lymphocytes per 100 enterocytes
Marsh II	Lymphocytic enteritis with crypt hyperplasia: intraepithelial lymphocytosis and elongation and branching of crypts in which there is an increased proliferation of epithelial cells
Marsh III	Intraepithelial lymphocytosis, crypt hyperplasia, and villous atrophy. There are 3 distinct stages of villous atrophy
Marsh IIIA	Partial villous atrophy, the villi are blunt and shortened. Arbitrarily, samples are classified as partial villous atrophy if the villus-crypt ratio was less than 1:1
Marsh IIIB	Subtotal villous atrophy, villi are clearly atrophic, but still recognizable
Marsh IIIC	Total villous atrophy, villi are rudimentary or absent, and the mucosa resemble colonic mucosa.

Modifications to this scoring system have been proposed[53,54]. Oberhuber et al[55] suggested that Marsh III lesions should be included into a, b, and c categories. However, Marsh et al[52] examined these subdivisions by means of correlative light and scanning electron microscopy, and demonstrate that Oberhuber’s classification is untenable. In their view, this categorization reflects misinterpretations of the real architectural contours of flat mucosae.