Midgut carcinoids (MCs) account for a third of all GICTs and 25 per cent of all small bowel tumours. They are more common in the 6th and
7th decades, predominant in males and represent the most common cause of the carcinoid syndrome (4). They are usually multicentric, located in the distal ileum and thought to arise from serotonin producing intra-epithelial endocrine Inhibitors,research,lifescience,medical cells. MCs have significant malignant potential with 50% to 60% of AZD9291 EGFR patients having metastatic disease at time of diagnosis (4). The patients usually have a long history of abdominal discomfort/pain which eventually require admission because of obstruction, perforation or gastrointestinal bleeding (3,15). The primary lesion in MCs is usually a small Inhibitors,research,lifescience,medical (<1 cm), flat and fibrotic tumour in the submucosal plane of the ileum and is frequently not diagnosed until surgical exploration. Other operative findings usually include enlarged lymph nodes with associated adjacent mesenteric fibrosis (3) leading to kinking of the bowel and thus obstruction Inhibitors,research,lifescience,medical (10,16). This extensive mesenteric stranding and fibrosis is probably secondary to the release of serotonin and growth factors (from tumour cells) and can also lead to the encasement of mesenteric vessels leading to
ischemia of the bowel (10). Appendiceal carcinoids are the most common malignant tumours of the appendix and are diagnosed incidentally in 0.3-0.9 per cent of patients undergoing appendicectomy (17). They are usually diagnosed in Inhibitors,research,lifescience,medical the fourth and fifth decades of life
(11). Appendiceal carcinoids are more common in women (11), usually located in the distal third of the appendix where they do not cause any obstruction and thus remain asymptomatic (18). Size of the tumour is considered to be of prognostic value with more than 95 per cent of appendiceal carcinoids being less than 2 cm and rarely metastasising (19). Inhibitors,research,lifescience,medical In such patients, simple appendicectomy is curative whereas those whose tumours are greater than 2 cm, should in addition be treated with right hemicolectomy (18). Treatment for lesions between 1 and 2 cm is controversial and the decision for right hemicolectomy Cilengitide depends on factors like mesoappendiceal invasion, vascular invasion, mitotic activity, proliferation markers and patient risk factors (20,21). Goblet cell appendiceal carcinoids tend not to produce a grossly visible tumour mass but diffusely infiltrate the wall and have features of both carcinoid and adenocarcinoma (22,23). These patients should be offered hemicolectomy. Colonic carcinoids account for about 12% of all carcinoid tumours but only 1% of colonic tumours.