The treatment for tumors varies. Small carcinoids (<2 cm) without features of malignancy may be treated by appendectomy if complete removal is possible. Other carcinoids and adenocarcinomas may require right hemicolectomy.
Pseudomyxoma peritonei treatment includes cytoreductive surgery which includes the removal of visible tumor and affected essential organs within the abdomen and pelvis. The peritoneal cavity is infused with heated chemotherapy known as HIPEC in an attempt to eradicate residual disease. The surgery may or may not be preceded or followed with intravenous chemotherapy or HIPEC.
A study of primary malignacies in the United States found a rate of 0.12 cases per 1,000,000 population per year. Carcinoids that were not identified as malignant were not included in this data. Carcinoid is found in roughly 1 in 300 appendectomies for acute appendicitis. A Hong Kong case series of 1492 appendectomies identified 17 neoplasms. Eight were carcinoids without specification of malignant features. Three cases of adenocarcinoma, and one each of cystadenocarcinoma, psedomyxoma peritoneii, and metastasic carcinoma were identified. The remaining tumors were benign. It was previously believed that carcinoid tumors are the most common tumors of the appendix but now data from SEER ( Surveillane, epidimology and End results) show that mucinous adenocarcinomas are more common
McGory, Marcia L.; Maggard, Melinda A.; Kang, Hakjung; O'Connell, Jessica B. et al. (2005). "Malignancies of the appendix: Beyond case series reports". Diseases of the Colon & Rectum48 (12): 2264–71. doi:10.1007/s10350-005-0196-4. PMID16258711.