sites of carcinoid tumours

Last reviewed 03/2023

Carcinoid tumours may occur where there are Kulchitsky cells:

  • gastrointestinal tract - in order of frequency:

    • mid-gut:
      • 60% of cases
      • particularly distal third of appendix and terminal ileum
      • rarely in a Meckel's diverticulum

    • hindgut:
      • 10-20% of cases
      • usually rectum

    • foregut:
      • 10-20% of cases
      • mainly stomach, but also duodenum and oesophagus

  • outside the GI tract:
    • bronchus
    • testes
    • ovaries

Potential to metastasise is related to site and size:

  • appendix 3% metastasise, ileum 30% metastasise
  • less than 1 cm, 2% metastasise; 1-2 cm, 50% metastasise; more than 2 cm, 80% metastasise

Appendiceal carcinoids are rarely multiple; ileal carcinoids are multiple in 30%.