Appendiceal cancer : a review of the literature.

Primary appendiceal cancer is rare and most commonly found incidentally on a surgical specimen after appendectomy for acute appendicitis. This small organ gives rise to different subtypes which are histological and biological distinct. Historically the classification of these tumors has been confusing because of the different nomenclature that is used. This review has broadly classified them into four subgroups: colonic-type adenocarcinoma, mucinous neoplasm, goblet cell carcinoma and neuroendocrine neoplasm. Signet ring cells is not considered as a distinct subgroup but as a histologic feature that can be present in colonic-type adenocarcinoma and mucinous neoplasms. As staging and management of appendiceal tumors depend on these subtypes, an adequate classification of them is important. This review aimed to give an overview of the epidemiology, grading and staging, management and prognosis of these neoplasms. Despite its rarety, specific staging systems and treatment guidelines exist for some subtypes. For other subtypes staging systems and management is extrapolised from colorectal cancer because of the lack of randomised, prospective trials.