The carcinoid tumour.

Carcinoid tumours are by no means rare. The wide range of sites in which they occur is explained by their origin from APUD cells of the neural crest. These cells migrate to all parts of the alimentary tract during embryonic life, and ultimately are found as well in various gut derivatives such as the respiratory, pancreatic and biliary systems. On the basis of a series of 31 carcinoid tumours seen at the Royal Prince Alfred Hospital in a five-year period, the distinctive clinical and histological features of carcinoids of foregut, midgut and hindgut origin are reviewed. Diagnosis, treatment and results are discussed, and recommendations regarding management of the patient with a carcinoid tumour are given.