ABSTRACT
Tumors of the vermiform appendix represent less than 0.5% of all gastrointestinal malignancies and of all appendectomy pathology specimens. There are three distinct histological types: carcinoid, mucinous adenocarcinoma (or malignant mucocele), and colonic-type adenocarcinoma. Another variant of adenocarcinoma, termed adenocarcinoid, was recently added to this group. Their reported frequency and age at presentation are shown in Table 1. These histological variants have different clinical presentations, biological behavior, prognosis, and thus treatment. Appendiceal tumors are infrequently diagnosed preoperatively or during surgery. They usually present as an unexpected finding following an incidental appendectomy, or after an appendectomy for the clinical diagnosis of appendicitis. Hence, patients with appendiceal malignancies frequently require a second procedure for complete treatment. A synchronous or metachronous second malignancy is common in these patients (15-35%). More than 50% of the second malignancies are in the gastrointestinal tract, particularly the colon and rectum. Hence all patients with appendiceal tumors should be routinely evaluated and observed for a synchronous or metachronous second cancer.
