A National Long-Term Study of Neuroendocrine Tumors of the Appendix in Children: Are We Too Aggressive?

Introduction Pediatric neuroendocrine tumors (NETs) of the appendix are mostly detected incidentally after appendectomy for acute appendicitis. NET management is a matter of controversy. In this national, multicenter study, we aimed to establish guidelines based on our results and the literature. Materials and Methods Medical records of children (0–16 years) with NET of the appendix, treated in Switzerland (1991–2012), were reviewed. Results Forty cases (28 girls) were analyzed. Median age at diagnosis was 12.7 years (interquartile range [IQR]: 4.0). Tumor size was 0.1–24 mm (median: 0.6, IQR: 0.6). Four patients (10%) underwent additional surgery because of either tumor size > 15 mm (1/4), extension to the mesoappendix (1/4), or incomplete resection (2/4). Three patients with a tumor of ≥ 20 mm had no additional surgery. No patient had lymph node metastases. All patients were in complete remission at the last follow-up (median: 3.0 years, IQR: 10.9). Conclusion We conclude from this study and from an extensive review of the literature that two criteria may point to the need for additional surgery, i.e., the possibility of regional lymph node involvement: tumor size > 20 mm and incomplete surgical resection margins. Childhood NET of the appendix has an excellent prognosis.