ENDOCRINE TUMORS OF THE SMALL AND LARGE-INTESTINE

Among endocrine tumors arising in the intestinal tract, midgut argenta ffin EC cell carcinoids, duodenal gastrin cell tumors and rectal trabe cular L cell carcinoids, in order of decreasing frequency, are those b etter represented. Together they account for more than 80% of such tum ors. Duodenal somatostatin cell tumors, gangliocytic paragangliomas an d poorly differentiated neuroendocrine carcinomas, are also well defin ed tumor entities. The carcinoid syndrome with intermittent flushing, hypotension and diarrhea, and the Zollinger-Ellison syndrome with seve re peptic ulcer disease, are the only hyperfunctional syndromes consis tently found in association with these tumors. The carcinoid syndrome arises in about 10% of intestinal carcinoids, usually in their advance d metastatic stage. The Zollinger-Ellison syndrome occurs in associati on with about 40% of gastrin cell tumors, including small intramural g rowths. Tumor prognosis depends on mode and site of presentation, hist ology, cell type(s), size, level of invasion, metastases (especially d istant metastases) and associated clinical syndrome or background dise ase.