A 45-year-old woman undergoes appendicectomy for appendicitis. Histology reveals a 1.8 cm well-differentiated neuroendocrine tumor (NET) at the tip of the appendix with no lymphovascular invasion and clear margins. According to ENETS 2016 guidelines, the next management step is:

• A Right hemicolectomy — all appendiceal NETs require formal resection
• B Chromogranin A measurement and repeat CT in 6 months
• C Sandostatin LAR therapy to prevent metastasis
• D No further surgery — appendicectomy is curative for NETs <2 cm without adverse features ✓

Explanation

ENETS and ESMO guidelines specify that appendiceal NETs <2 cm (most common presentation, 70-95% of appendiceal NETs) with no lymphovascular invasion, clear resection margins, no mesoappendiceal invasion >3 mm, and low Ki-67 (<2%) are adequately treated by appendicectomy alone — 5-year survival approaches 100%. Right hemicolectomy is recommended for: tumors >2 cm, any size with lymphovascular invasion or mesoappendiceal involvement >3 mm, positive or uncertain margins, or goblet cell carcinoid/mixed adenoneuroendocrine carcinoma (MANEC). At 1.8 cm without adverse features, no further surgery is needed; however, some guidelines still discuss 1.5-2 cm as a grey zone.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.