Appendix Neoplasms

Pathology of the vermiform appendix is commonly encountered by surgeons, most frequently in patients presenting with acute appendicitis. After surgical removal of the appendix, a very small proportion (1%) will contain a tumour. Occasionally patients present with chronic symptoms, by which time the disease process is usually well established. The most common tumours found in the appendix are neuroendocrine tumours. Whilst most are treated adequately with appendicectomy alone, a proportion of these tumours are at higher risk of both lymph node and distant metastases, justifying a more radical surgical approach. Appendiceal mucinous neoplasms and adenocarcinoma of the appendix are rare tumours, the management of which is undertaken in centralised services. Rather than metastasising through lymphatic or haematogenous routes, these tumours have a greater propensity for seeding and spread throughout the peritoneal cavity. When this occurs from an appendiceal mucinous neoplasm, the condition is known as pseudomxyoma peritonei. Given the route of metastasis, treatment is focussed on the peritoneal cavity with cytoreductive surgery entailing removal of all macroscopic tumour deposits and heated intraperitoneal chemotherapy. The role of chemotherapy is currently limited but evolving as the understanding of the biology of these rare tumours grows. Whilst aggressive forms of these tumours do exist, prognosis for many is good with the disease process often following an indolent course. Knowledge of these conditions is essential to ensure recognition and appropriate referral to specialist centres.