A spotlight on Appendiceal Neuroendocrine Neoplasms
What are Appendiceal NENsAppendiceal Neuroendocrine Neoplasms (NENs) account for approximately 60% of all primary cancers in the appendix. The other main cancer types found in the appendix are regular adenocarcinomas (including signet ring cell and goblet cell) and mucinous neoplasms such as Pseudomyxoma Peritonei (PMP) or Low-Grade Mucinous Neoplasms (LAMD). Appendiceal neuroendocrine tumours (aNET) (i.e. well differentiated) account for 75% of all aNENs, are mostly indolent tumours treated effectively with simple appendectomy. In fact, most are incidentally found upon presentation of right lower quadrant (RLQ) pain in keeping with appendicitis. They are typically (but not exclusively) diagnosed in younger patients. Poorly differentiated appendiceal Neuroendocrine Carcinomas (aNEC) resemble small-cell or large-cell neuroendocrine carcinomas of the lung, have aggressive behaviour, and usually present with metastatic disease at diagnosis.Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) are possible, particularly…
