Rectal Carcinoid Tumors: A Case Study

Carcinoid tumors are slow-growing neoplasms that derive from neuroendocrine cell. Rectal carcinoids or neuroendocrine tumors account for 12 - 27% of all carcinoid tumors (Modlin and Sandor 1997; Modlin, Lye et al. 2003). Although it accounts for < 1 - 2% of all rectal neoplasia, the prevalence of rectal carcinoid is increasing partly due to increased colorectal cancer screening (Modlin, Oberg et al. 2008; Murray, Sippel et al. 2012). Majority of rectal carcinoids are diagnosed incidentally. The prevalence of rectal carcinoid in adults undergoing screening colonoscopy ranges 0.05 – 0.07%, which is estimated to be 27,500 – 38,500 cases in the United Stated (Scherubl 2009). In a large United States-based databases comprising patients with rectal …show more content…
2007; Shields, Tiret et al. 2010). Generally, it is accepted that tumors larger than 20 mm should generally be managed similarly to rectal adenocarcinoma with radical resection due to high risk of lymph node metastasis (Anthony, Strosberg et al. 2010). Controversies exit regarding optimal management of small rectal carcinoid tumors. The North American Neuroendocrine Tumor Society (NANETS) recommended that because of their low risk of metastatic spread, tumors that are <1-2 cm in size and confine to the mucosa or submucosa (T1) can be managed with endoscopic resection (Anthony, Strosberg et al. 2010). The European Neuroendocrine Tumor Society (ENET) guidelines endorse lesions smaller than 1 cm can be completely resected endoscopically or by another local transanal technique. However, the outcome of a lesion between 1 and 2 cm is unclear.(Caplin, Sundin et al. 2012). In contrast, large Asian case series found that lymph nodes metastasis of colorectal carcinoids occurred up to 7 – 9.7 % in the tumor ≤ 10 mm (Soga 2005; Konishi, Watanabe et al. 2007). In Japan, rectal carcinoids that > 10 mm are treated surgically similar to treatment of rectal adenocarcinoma (Konishi, Watanabe et al. 2007; Scherubl