An Update on Appendiceal Neuroendocrine Tumors

Curr Treat Options Oncol. 2023 Jul;24(7):742-756. doi: 10.1007/s11864-023-01093-0. Epub 2023 May 4.

Abstract

The mainstay of appendiceal neuroendocrine neoplasm (aNEN) treatment is surgery, based on simple appendectomy or right-sided hemicolectomy with lymphadenectomy (RHC). The majority of aNENs are adequately treated with appendectomy, but current guidelines have poor accuracy in terms of selecting patients requiring RHC, especially in aNENs 1-2 cm in size. Simple appendectomy is curative for appendiceal NETs (G1-G2) < 1 cm (if the resection status is R0), whereas RHC with lymph node dissection is recommended in tumors ≥ 2 cm in diameter, based on the high risk of nodal metastases in these cases. The clinical management of aNENs 1-2 cm in size is more controversial because lymph node or distant metastases are uncommon but possible. In our opinion, patients with tumor size > 15 mm or with grading G2 (according to WHO 2010) and/or lympho-vascular invasion should be referred for radicalization with RHC. However, decision-making in these cases should include discussion within a multidisciplinary tumor board at referral centers with the aim of offering each patient a tailored treatment, also considering that relatively young patients with long-life expectancy represent the majority of cases.

Keywords: Appendiceal tumor; Right-side hemicolectomy; Size; WHO; aNEN.

Publication types

  • Review

MeSH terms

  • Appendectomy
  • Appendiceal Neoplasms* / diagnosis
  • Appendiceal Neoplasms* / surgery
  • Humans
  • Lymph Nodes / pathology
  • Neuroendocrine Tumors* / diagnosis
  • Neuroendocrine Tumors* / surgery
  • Retrospective Studies

Supplementary concepts

  • Gastro-enteropancreatic neuroendocrine tumor