Carcinoid tumour of the appendix.
BACKGROUND: Appendiceal carcinoid tumours are found in 0.3-0.9 per cent of patients undergoing appendicectomy. Controversy exists over the management following appendicectomy, especially with regard to the role of right hemicolectomy in patients with tumours smaller than 2 cm in diameter. METHODS AND RESULTS: The literature pertaining to the behaviour of appendiceal carcinoids was reviewed in order to formulate indications for right hemicolectomy. Metastatic disease from appendiceal carcinoids is a rare occurrence, but is more common when lesions are larger than 2 cm in diameter. The risk-benefit balance of right hemicolectomy needs to be better defined, and an improved understanding of tumour cell biology may aid prognostic accuracy and decision-making. CONCLUSION: There is limited evidence on which to base clear indications for right hemicolectomy in patients with a diagnosis of appendiceal carcinoid. Acceptable indications are carcinoids larger than 2 cm in size, any high-grade malignant carcinoid (including those with a high mitotic index), mesoappendiceal invasion, lesions at the base of the appendix with tumour-positive margins, and goblet cell adenocarcinoid tumours.