Clinical features and diagnosis of alimentary endocrine tumours.

The alimentary tract is the largest endocrine factory in the body. The different types of endocrine cells, their distribution in the gastrointestinal tract, and their products are illustrated in Fig. 1. Some of the peptides and amines which are produced are established hormones, exerting physiological control of bodily functions, while the roles of others have not yet been determined. Some are produced by one organ only (for example insulin and glucagon by the pancreas), while others originate in more than one part of the gastrointestinal tract (for example gastrin from both the gastric antrum and the upper small intestine, and SHT from three types of cell in