Neuroendocrine tumor of the appendix: Twelve years of results from a single institution

BACKGROUND: The aim of this study was to investigate the incidence of appendiceal neuroendocrine tumors (NET) in an acute appendicitis cohort, as well as to investigate the behavioral form of the tumor. Our secondary aim was to investigate survival in patients with appendiceal NET. METHODS: Between February 2006 and June 2018, 6518 appendectomies were performed for acute appendicitis in the department of surgery, University of Health Sciences, Okmeydani Education and Research Hospital, Istanbul, Turkey. The medical records of these consecutive 6518 appendectomy patients were evaluated retrospectively. After the histopathological analysis, a total of 22 patients were identified as cases of appendiceal NET. These patients were included in the study. A retrospective analysis of data including gender, age, intraoperative surgical findings, duration of postoperative follow-up and survival, tumor localization, the diameter of the tumor, tumor grade, invasion, surgical margin, and stage of the tumor was performed. RESULTS: The incidence of appendiceal NET was 0.33%. Eleven patients were diagnosed as primary pathological stage pT1aN0M0 according to the European Neuroendocrine Tumor Society guidelines. One patient was diagnosed as primary pathological stage pT1bN0M0, and 10 patients were diagnosed as primary pathological stage pT2N0M0. The median tumor diameter was 7.6 mm. There was no patient with a tumor diameter greater than 20 mm. CONCLUSION: The incidence of appendiceal NET in our study is consistent with that stated in the literature. The results of our research suggest that further surgical procedures for NETs that occur coincidentally in patients of the AA cohort are often unnecessary. In addition, the study revealed that disease-free survival (100%) was good over a mean follow-up of 59.2 months.