Arterial inflammatory-cell infiltration in Crohn's disease.

Histologic sections from 70 cases of Crohn's disease were studied for the presence of acute and/or chronic inflammatory cells in the walls of arteries and arterioles. Vessels in areas of marked inflammation were not considered. Similarly, arteries showing chronic obliterative changes, without inflammatory cells, were excluded. More than 20% of the cases showed either chronic inflammatory-cell infiltration, acute and chronic inflammatory-cell infiltration, obliterative changes with inflammatory-cell infiltration, or granulomatous inflammation. These changes need to be recognized as a part of Crohn's disease; furthermore, physicians should refrain from designating patients as having one of the primary vasculitides in the absence of extraintestinal evidence of disease.