Acute appendicitis confined to the appendiceal tip: evaluation with graded compression sonography.

Focal appendicitis at the tip of the appendix has not been emphasized in the sonographic literature. We present the sonographic findings in four patients with pathologically confirmed acute appendicitis confined to the appendiceal tip. In all four patients, the base of the appendix had a normal appearance with maximal outer diameters measuring 4 to 6 mm. However, the inflamed tip was focally enlarged, measuring greater than 7 mm. The importance of a careful survey of the entire length of the appendix is emphasized to avoid a false-negative examination.