- The benign tumours include adenomatous polyps, mucus cystadenoma, fibromas, and neuromas.
-A mucus cystadenoma may obstruct the appendicular lumen and from a mucocele. - The malignant tumours comprise carcinoid tumours, adenocarcinoma, and lymphomas.
- Carcinoid tumour (argentaffinoma)
-Appendix is common site for carcinoid tumour and rarely metastases or gives rise to carcinoid syndrome.
-It is moderately hard and on sectioning the appendix seen as a yellow tumour between the intact mucosa and peritoneum.
-Appendicectomy is sufficient treatment unless the caecal wall is involved or tumour is 2cm or more in size or involved lymph nodes are found, when right hemicolectomy is indicated.
Primary adenocarcinoma
- Primary adenocarcinoma of the appendix is extremely rare and are of two subtypes – mucinous and colonic.
- The treatment is right hemicolectomy (as a second procedure if the condition is not recognized at the first operation).
- A mucus-secreting adenocarcinoma of the appendix may rupture into the peritoneal cavity, seeding it with mucus-secreting malignant cells.
- Presentation is late as gross abdominal distension as a result of pseudomyxoma peritonei, which may mimic ascites
- The possible sequelae include adhesions, obstruction to the gut, and fistula formation.
- Treatment consists of radical resection of all involved parietal surface and aggressive intraperitoneal chemotherapy.