Which of the following features would be more consistent with Crohn’s disease than with ulcerative colitis?

a. Transmural inflammation

b. Microscopic evidence of granulomas within mucosal biopsies

c. Microscopic evidence of submucosal thickening and fibrosis

d. Microscopic evidence of submucosal inflammation

Transmural changes are found in Crohn’s disease of the colon in which all layers of the colonic wall may be involved in a granulomatous inflammatory process. In its earliest stages, the lesions consist of infiltration of round cells and polymorphonuclear leukocytes into the crypts of Lieberkühn at the base of the mucosa. Crypt abscesses are common. Microscopy reveals vacuolization of overlying epithelial cells, swelling of mitochondria, and widening of intercellular spaces. Submucosal thickening and fibrosis associated with recurrent submucosal inflammation are more common in Crohn’s disease than in ulcerative colitis.