Mucocoele and mucinous tumours of the appendix: A review of the literature

• Mucocoele of the appendix contributes 0.2–0.7% of all appendiceal pathologies.
• Benign causes are epithelial hyperplasia or obstruction by stricture or faecolith.
• Neoplastic lesions include cystadenomas and malignant mucinous cystadenocarcinomas.
• The most common symptoms are abdominal pain and a right iliac fossa mass.
• Malignant mucocoele can progress to pseudomyxoma peritonei if incorrectly managed.

IntroductionMucocoele of the appendix is rarely encountered but consultant general surgical and trainees must be aware of it as a differential diagnosis, due to the nuances associated with its management. We aimed to provide a comprehensive review of the current literature concerning this rare surgical pathology.MethodsSearch terms “appendi*”, “tumour”, “malignancy”, “mucino*” and “cystadenoma” were used in combination to identify papers from PubMed. Abstracts and full text were manually reviewed to identify suitable papers.ResultsFull search results included 311 articles. Review of titles and abstracts led to further full text review of 46 articles. Of these 30 were selected for inclusion based on relevance, adequate sample size and recent publication date.DiscussionMucocoele of the appendix describes dilatation with associated luminal mucin and can result from benign and malignant processes. It contributes 0.2–0.7% of all appendiceal pathologies. The most common presenting symptoms are abdominal pain and a palpable mass in the right iliac fossa. Computed tomography of the abdomen and pelvis is key in facilitating diagnosis, although CEA and CA19-9 also have a role. The major complication of malignant causes of mucocoele is progression to pseudomyxoma peritonei. Treatment is surgical with or without chemotherapy depending on the underlying cause. Prognosis depends on aetiology.ConclusionMucocoele of the appendix is a rare diagnosis. However, given the possibility of neoplastic peritoneal dissemination, it should be considered as a diagnosis, especially in older females with non-specific symptoms similar to appendicitis.