Endocrine cell hyperplasia and appendiceal carcinoids.

As endocrine tumours in a number of organs may arise in a background of hyperplasia, the density of endocrine cells in appendices from ten patients with carcinoid tumours was compared with that in appendices from ten age- and sex-matched control patients. Crypt and lamina propria endocrine cells were quantified separately. The density of argentaffin endocrine cells in the crypts was significantly higher in appendices with carcinoid tumours when compared with the controls. No difference was found in non-argentaffin endocrine cells, and no difference was found in either argentaffin or argyrophil endocrine cells in the lamina propria. While it is possible that carcinoid tumours induce an increase in the number of enterochromaffin (EC) cells in the background mucosa, it is considered more likely that EC cell hyperplasia predisposes to the development of carcinoid tumours of the appendix.