A case of a horseshoe appendix

Abstract

Anomalies of the appendix are extremely rare, and a horseshoe appendix is even rarer. A literature search has revealed only five reported cases. In this report, we present a case of a horseshoe appendix.A 78-year-old man was referred for further examination following a positive fecal occult blood test. A mass in his ascending colon was detected on colonoscopy, while computed tomography showed that it was connected to the appendix. Tumor invasion derived from the ascending colon or appendix was suspected. We diagnosed ascending colon cancer prior to laparoscopic ileocecal resection. Macroscopic findings showed that the appendix connected to the back side of the mass, while microscopic findings showed that the mucosa and submucosa were continuous from the appendiceal orifice in the cecum to the other orifice in the ascending colon, where a type 1 tumor was observed on the orifice. We eventually diagnosed the patient with tubulovillous adenoma and a horseshoe appendix.A horseshoe appendix communicates with the colon at both ends and is supplied by a single fan-shaped mesentery. Cases are classified by the disposal of the mesentery and the location of the orifice. Anatomical anomalies should be considered despite the rarity of horseshoe appendices.

Fistulae involving the appendix: a systematic review of the literature

“…[103][104][105][106][107] Appendiceal fistulae to the GI tract included 10 cases to the sigmoid colon alone, [108][109][110][111][112][113][114][115][116][117] with an additional two concurrently fistulating to the bladder. 118,119 There were 21 cases of fistula to the ileum, 84,[120][121][122][123][124][125][126][127][128] two to the jejunum, 84,129 six to the duodenum, 84,[130][131][132][133] eight to the caecum, 84,[133][134][135][136][137][138] three to the ascending colon, 48,139,140 one to the transverse colon, 141 one to the rectum, 142 and one to a gastrojejunal anastomosis from prior gastroenterostomy. 143 In three cases, fistulae invol...…”

“…159 Other presumed congenital communications include four cases of horseshoe appendix. 134,135,137,140 A 'bridge' between the appendix and the terminal ileum has also been described and was reported to be an anatomical variant; 126 however, the embryological plausibility of this presumption is questionable. Three cases of cystic fibrosis with appendiceal fistula have been reported.…”

“…Notable outliers include a presumed anatomical communication between the appendix and ileum in a 68-year-old patient 126 (see above) and a horseshoe appendix in a 78-year-old male. 140 Infection Infectious and inflammatory causes tend to affect young to middleaged adults. The main causes include appendicitis, diverticulitis, inflammatory bowel disease, amoebiasis, actinomycosis and tuberculosis which have occurred in patients between the ages of 17 and 63 years.…”

Horseshoe appendix: Anatomical variant

“…A horseshoe appendix is an extremely rare anomaly where the appendix has two communications with the caecum, one at either end, creating a loop. Since the first case report in 1989 a total of 7 cases have been reported . None of the reported cases of horseshoe appendix were identified preoperatively.…”

“…Takabatake et al . describe these as being congenital and proposed further modifications to the existing classification of appendiceal anomalies to subtype patterns of horseshoe appendix …”