Review article: current status of gastrointestinal carcinoids

Abstract

Carcinoid tumours are enigmatic, slow growing malignancies which occur most frequently (74%) in the gastrointestinal tract. In recent years, it has become apparent that the term `carcinoid' represents a wide spectrum of different neoplasms originating from a variety of different neuroendocrine cell types. Carcinoid lesions are usually identified histologically by their affinity for silver salts, by general neuroendocrine markers, or more specifically by immunocytochemistry using antibodies against their specific cellular products. Within the gut, the most frequent sites are the small bowel (29%), the appendix (19%) and rectum (13%). Clinical manifestations are often vague or absent. Nevertheless, in approximately 10% of patients the tumours secrete bioactive mediators which may engender various elements of characteristic carcinoid syndrome. In many instances the neoplasms are detected incidentally at the time of surgery for other gastrointestinal disorders. The tendency for metastatic spread correlates with tumour size, and is substantially higher in lesions larger than 2.0 cm. An association with noncarcinoid neoplasms is ascribed in 8–17% of lesions. Treatment consists of radical surgical excision of the tumour, although gastric (type I and II) and rectal carcinoids may be managed with local excision. Overall 5‐year survival is excellent for carcinoids of the appendix (86%) and rectum (72%), whereas small intestinal (55%), gastric (49%) and colonic carcinoids (42%) exhibit a far worse prognosis.

Gastroenteropancreatic Neuroendocrine Tumours – An Institutional Experience

“…The NETs occur 6.5-8.4 times more frequently in ileum than in duodenum and jejunum [13]. Even though primary tumour was only 2.5 cm, it had already metastasized to the liver and this is in accordance to studies conducted by Kaltsas et al [14].…”

“…This patient had regional lymph node metastasis at time of diagnosis According to Modlin et al [2] colonic carcinoids are large tumors and commonly present with liver metastasis. Lauffer et al [13] indicated that colonic carcinoids had a female predominance with average age of 70 at the time of diagnosis, but in the present series all of the cases were men.…”

“…Grossly it was a polypoidal growth of size 2x 1 cm. According to Lauffer et al [13] there is no gender preponderance for rectal carcinoids and average age at diagnosis is 58.8 years. Also these lesions are generally small, sessile or polypoidal and are usually identified after bleeding episodes.…”

Neuroendocrine tumours.

“…Table 3 summarizes the frequency of carcinoid at different sites (most occurring in the gut at 67.5%, then the lung at 25.3%), with the associated 5-year survivals. Predisposition to metastatic spread depends on location and size (Lauffer et al 1999, Modlin et al 2003.…”

Circulating markers of prognosis and response to treatment in patients with midgut carcinoid tumours

“…1 2 The majority of cases have metastases at the time of diagnosis 3 and surgical cure is frequently not possible. Variation in their clinical behaviour and several potential treatment options make predicting prognosis desirable.…”