colorectal carcinoid tumor
Carcinoid tumors of the colon are extremely rare tumors, representing <11% of all carcinoid tumors and only 1% of colonic neoplasms.
Though they are thought to arise from serotonin-producing epithelial endocrine cells disseminated throughout the colon, carcinoid syndrome is rare in these patients, presenting in <5% of cases.
Typically, carcinoid tumors of the colon present in the sixth to seventh decade of life during evaluation for anorexia, abdominal pain, and unintentional weight loss.
Data from several series demonstrate that carcinoid tumors of the colon are diagnosed late in the course of the disease, and the average size of these tumors was approximately 5 cm at diagnosis.
Additionally, at diagnosis, approximately two thirds of patients have local nodal or distant metastases, resulting in an overall 5-year survival rate of 25%–41%.
Treatment
Shebani and colleagues demonstrated that nearly 55% of patients with carcinoid tumors involving the colon present with liver or nodal metastases.
Given this propensity for metastatic spread, most experts suggest a formal hemicolectomy with mesenteric resection as the preferred treatment for all carcinoid tumors of the colon.
Like appendiceal carcinoids, the size of rectal carcinoid tumors is closely correlated with metastatic risk and long-term survival rates.
Rectal carcinoids <2 cm rarely metastasize, directing the conclusion that for these smaller lesions local excision is sufficient; for lesions >2 cm, a low anterior resection or abdominal perineal resection should be performed provided distant metastases are absent.
See also
carcinoid tumors
- digestive carcinoid tumor
- recatl carcinoid tumor