What is the most common tumor of the appendix?
- Carcinoid is the most common tumor of the appendix, and the appendix is the most common site of carcinoid tumors.
- Most large series report an incidence of 0.2 to 0.3 in appendectomy specimens.
- Simple appendectomy is appropriate for distal tumors that are less than 1 cm in size.
- If the tumor is greater than 2 cm or has extension into the mesoappendix or base of the cecum, formal right hemicolectomy is indicated.
- For tumors between 1 and 2 cm that do not involve the base of the appendix, factors such as lymphovascular invasion and mitotic activity influence management decisions and should be referred to a tertiary care center.
- It is important to note that not all carcinoid tumors are malignant.
- The most common malignant tumor is mucinous adenocarcinoma, composing more than 60% of all appendiceal malignancies.
- A mucocele is the second most commonly encountered tumor of the appendix, in which a distended appendix is secondary to obstruction of the appendiceal orifice by mucoid material. Cysts smaller than 2 cm are almost always benign, whereas larger tumors may harbor malignancy.
- Rupture of these cysts may spread epithelial cells in mucoid fluid throughout the peritoneum, or pseudomyxoma peritonei of appendiceal origin.
