MUC5AC and Granuloma: The main diagnostic microscopic findings are crypt and villous abnormalities, including irregularity and blunting or broadening of the villi, maintained or increased mucin secretion by the epithelial cells, pseudopyloric metaplasia, irregular distribution of the Paneth cells in the crypt, chronic active inflammation in the lamina propria with neutrophilic cryptitis, crypt abscess, surface erosion and ulceration, and the presence of fibrosis and granuloma (Figures 3 and 4).