What is a carcinoid of the appendix?
Carcinoid tumors are the most common tumor of the appendix, accounting for more than half of all appendiceal malignancies and discovered in seven of every 1,000 appendectomy specimens. They account for 5% of GI carcinoids and are more common in women than men. The mean age at presentation is 49 years. This may reflect the common patient age at appendectomy, when the tumors are often incidentally discovered. Approximately two-thirds of appendiceal carcinoid tumors arise in the tip of the appendix, where they are unlikely to cause symptoms of obstruction. Ten percent of appendiceal carcinoids occur in the base where they are more prone to obstruct the appendix and cause acute appendicitis. It has been proposed that the incidence of appendiceal carcinoid tumors parallels the activity of subepithelial NE cells, the source of these tumors. The density of these NE cells peaks in the second decade of life and then decreases.