Right salpingo-ovarian and distal ileal entrapment within a paracaecal hernia presenting as acute appendicits

Pericaecal hernias are a rare subgroup of internal abdominal hernias that present with abdominal pain and occasionally with features of bowel obstruction.

A 72 year old female presented with a 24-h history of sharp, localised right iliac fossa pain, and no other symptoms. Clinical examination confirmed localised peritonism in the right iliac fossa. A tentative diagnosis of acute appendicitis was considered but in view of age a CT scan was performed. An area of abnormality in the right iliac fossa region was noted. At laparoscopy a macroscopically normal appendix and caecum was found. A smooth non-indentable mass in the lateral right iliac fossa contained loops of distal ileum, passing through a retro-caecal mesenteric defect consistent with a paraceacal hernia, with entrapment of the right ovary and fallopian tube. A right salpingectomy as performed and subsequent histopathological examination confirmed infarction of the fallopian tube.

Internal abdominal hernias are reported to have a post mortem incidence ranging between 0.2 and 0.9% of which only 10-15% are accounted for by pericaecal hernias. Types of pericaecal hernias include: ileocolic, retrocaecal, ileocaecal and paracaecal. These hernias are predisposed by the embryological development of the caecum retracting to the posterior abdominal wall and forming potential fossae.

This case highlights the need to consider a pericaecal hernia as a differential cause of right iliac fossa peritonism, and an indication for radiological imaging such as CT scan when the history is atypical for acute appendicitis.