Most patients presenting with right lower quadrant pain are clinically
suspected to have acute appendicitis, However, sonographic findings o
ther than appendicitis are detected in patients who are referred for u
ltrasound to rule out appendicitis. This pictorial essay delineates a
number of unsuspected pathological conditions revealed by ultrasound e
xamination of the right lower quadrant that do not involve the appendi
x but closely mimic acute appendicitis. Imaging studies play a signifi
cant role in preoperative diagnosis and determination of proper treatm
ent, The patient can undergo triage for proper further workup and surg
ical versus nonsurgical management. Acute appendicitis initially was c
onsidered on clinical presentation in all of our patients. The correct
diagnosis of other pathological conditions was made on the basis of s
onographic findings.