The neoplastic appendix: A practical approach

Neoplastic processes in the appendix are histologically similar to their colonic counterparts, and recognition of these neoplasms is relatively straightforward. However, reporting and tumour staging of the neoplastic appendix can be complex, given numerous proposed classification systems, the uncertainty surrounding extra-appendiceal spread, and the frequently low-grade histology. Prognostication and clinical decisions regarding treatment rely heavily upon the completeness of the pathology report. This review discusses the clinicopathologic features of the epithelial neoplasms of the appendix, including colonic-type (non-mucinous) adenomas and adenocarcinomas, mucinous neoplasms, classical carcinoid tumours (well-differentiated neuroendocrine tumours), and goblet cell carcinoids with a focus on prognosis, terminology and pertinent points to include in the pathology report.