Appendix carcinoids

Epidemiology of appendix carcinoids

The frequency of carcinoid tumors in unselected series of appendectomy specimens ranges from 0.2-0.9%. Although it is reported that appendiceal carcinoid occurs twice as often in women as in men, this observation may reflect the frequency of incidental appendectomy in gynaecological and gallbladder surgery. Appendiceal carcinoid tumor can occur at any age including in children, and the median age is in the fourth decade.

Symptomatology of appendix carcinoids
Almost all typical appendiceal carcinoid tumors are clinically silent and are discovered incidentally during surgery performed for symptoms of acute appendicitis or during incidental appendectomy in the course of other abdominal surgery procedures.

Histopathology of appendix carcinoids
Most typical appendiceal carcinoids occur in the tip of the organ. They are usually small and measure less than 1 cm, rarely more than 2 cm in diameter. Immunohistochemical carcinoid tumors of the appendix express general endocrine markers, such as CgA and synaptophysin and the proliferation rate is usually rather low. Mitotic figures less than 2 per 10 high power microscopic fields.

Biochemistry of appendix carcinoids
Most of the tumors are found incidentally with normal levels of general biochemical markers such as CgA and U-5-HIAA.

Topographical localisation of appendix carcinoids
In selected cases abdominal US or CT-scan and MRI may occasionally establish pre-operative diagnosis.

Treatment of appendix carcinoids
The gold standard is surgical treatment with resection of the appendix. If the tumor is larger than 2 cm or located at the base of the appendix a wider resection has to be performed with right hemicolectomy (see section for Surgery). Metastatic disease is treated in the same way as midgut carcinoids.