Case report: A rare presentation of right illiac fossa pain

Introduction

Duplex appendix is a rare congenital abnormality with an incidence of 2 in 50,000. Incidences of duplex appendicitis are a rare but recognised phenomenon. Unusual presentation of this congenital abnormality can lead to delays in diagnosis and management.

Case description

A 42-year-old male presented with a two-day history of right iliac fossa pain and raised inflammatory markers. He underwent diagnostic laparoscopy where a normal appendix was seen. Laparoscopic appendicectomy was not performed. He represents several years later with similar symptoms and another diagnostic laparoscopy was performed revealing a normal appendix. Subsequent laparoscopic appendicectomy was performed which was histopathology confirmed as a normal appendix. His symptoms did not improve after surgery and he developed localised guarding in the right iliac fossa, low grade pyrexia, tachycardia and raised inflammatory markers. An ultrasound scan was performed which was unremarkable. Computed tomography (CT) abdomen revealed a small collection from which extended a thin tubular structure ending in the terminal ileum. A third diagnostic laparoscopy was performed. The small collection was not identified and conversion to midline laparotomy revealed a second necrotic friable appendix leading to a retrocaecal and retroileal cavity (abscess). This was confirmed on histopathology to be a gangrenous appendix with secondary peritonitis. He was discharged from hospital several days post-operatively. A year later he represented to our services with an incisional hernia which was repaired laparoscopically.

Conclusions

Dual appendix is a well described but rare congenital abnormality that is well described by the Cave-Wellbridge classification. This congenital abnormality is often recognised incidentally at surgery or on post-mortem examination. Radiological studies are often not useful aids in making the diagnosis of duplicate appendix. Hence the possibility of a duplex appendix should be considered and sought during diagnostic laparoscopy performed in patients presenting with recurrent right iliac fossa symptoms.