[Diagnosis and treatment of gastrointestinal carcinoid. Report of a clinical case with duodenal site].

Carcinoid tumors are among the most frequently neuroendocrine neoplasms of the gastrointestinal tract. They occur more commonly as benign diseases but malignant ones can also be found. The peak age incidence varies with the location of the tumor, with appendiceal tumors being diagnosed at an overage of 36 years, whereas non appendiceal tumors are found typically in the fifth sixth decades of life. There is no sex predilection of the tumors. Most carcinoid tumors are found within the appendix (40-50%) or small intestine (25%). Less common sites include the rectum (15%), main bronchus (10%), duodenum (3-8%) and stomach (2%). Most carcinoid tumors are found incidentally at operation and cause no symptoms. If symptoms do occur, they can be either non specific include intermittent crampy abdominal pain, vomiting and distension caused by intestinal obstruction. The prognosis depends on the site of the tumor and its size. Most carcinoid tumors (75%) are less than 1 cm in size and only 5% are greater than 2 cm. The incidence of metastatic disease is related directly to the size of the tumor at all locations. Carcinoid tumor with size less than 1 cm give linfonodal metastasis only in 3-5%; the other with size over 2 cm give metastasis in the 70-75% of the cases. The 5-years survival for all carcinoid tumors are approximately 85%. Five years rate is higher (> 80%) in carcinoid tumors of appendix and rectum than in gastroduodenal, ileal and colonic neoplasm (< 60%). In this paper the authors report a case of malignant carcinoid of the duodenum.