Horseshoe appendix

Dr Daniel J Bell et al.

A horseshoe appendix is an extremely rare variant of the vermiform appendix, in which the appendix arises from the cecum and curves back on itself to re-insert into the cecum, similar to a semicircular canal in the inner ear.

Anatomic variation of the appendix is extremely rare. In a study of 50,000 appendix surgical specimens by Donald C Collins, an American general surgeon and pathologist, appendiceal agenesis was only seen in four cases, and duplication was seen in two cases, a prevalence of 0.004%. But no cases of horseshoe appendix were seen 1. In total eleven cases of horseshoe appendix have been reported in the English medical literature with a further four in the Chinese literature 1-9.

The appendix forms a loop with two appendiceal orifices and in theory at least acute appendicitis should be less likely as it is no longer a blind-ending tube, although at least one case has been described 2.

The first case was described as recently as 1989 by Thomas W Mesko, an American surgeon, and colleagues 1.

Article information

rID: 84112
Section: Anatomy
Tag: cases3
Synonyms or Alternate Spellings:
  • Horseshoe variant of the appendix
  • Horseshoe-shaped appendix
  • Horseshoe appendixes
  • Horseshoe appendices

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Figure 1: horseshoe
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.