Sonographic appearance of mucocele of the appendix

Mucocele of the appendix is an uncommon entity infrequently diagnosed prior to surgery or autopsy. Patients may be asymptomatic or present with a palpable right lower quadrant mass and/or pain. Barium enema findings are nonspecific and include nonfilling of the appendix and occasionally mass impression on the cecum. When visualized, calcification of the rim of a right lower quadrant mass may aid in diagnosis. The sonographic appearance in two cases is presented and compared with that in three other case reports in the literature, illustrating a spectrum of sonographic findings. Differential diagnosis is discussed.