Crohn disease of the ileocecal region: US visualization of the appendix.

In three of 52 consecutive patients with a painful mass in the right lower quadrant, ultrasound (US) disclosed severe mural thickening of the terminal ileum and cecum and moderate mural thickening of the appendix. In all three, the tentative diagnosis of Crohn disease was subsequently confirmed. If these US features are found in a patient with a suspected appendiceal mass, the diagnosis of Crohn disease must be seriously considered, and further evaluation is imperative.