Gastrointestinal Carcinoid Tumors

Isolated case reports and periodic reviews of the subject of carcinoid tumors have appeared in the medical literature for almost a century. The recent medical literature has been rich in papers dealing with the subject of carcinoid tumors due largely to the discovery of the malignant carcinoid syndrome as representing a clinical entity (1–12). The basic findings in this syndrome are chronic diarrhea, flushes and cyanosis, respiratory distress, and right-sided cardiac disease. The clinical syndrome has so far been described only in the presence of metastatic malignant carcinoids with large numbers of functioning cells, usually in the liver. For detailed pathological data with reference to sites, multiplicity, incidence, age, sex, and metastases, the reader is referred to the work of Ritchie (9). Gross Pathology The typical carcinoid tumor, which may occur in any portion of the gastrointestinal tract from the cardia to the anus, is a small submucosal nodule. Less often it is polypoid or annular in growth. The epithelium usually is intact, although occasionally it may be ulcerated. Infrequently, a large polypoid intraluminal growth occurs. Natural History and Course of the Disease It is generally agreed that carcinoid tumors arise from the Kulschitsky cells. MacDonald (12) has suggested that all extra-appendiceal carcinoids be considered malignant and reported in terms of invasiveness. He has suggested that these tumors be classified pathologically into four groups: Group 1: Non-invasive, confined to the mucosa and submucosa. Group 2: Invading the bowel wall muscle. Group 3: Invading the lymphatics or regional nodes. Group 4: Invading blood vessels or spreading to distant organs. Carcinoid tumors differ from most malignant neoplasms in the gastrointestinal tract, in the long duration of the disease. Long-term survivals, from one to two decades, are reported even in the presence of lymph-node involvement. Carcinoids of the Appendix Carcinoids located in the appendix are not detected by x-ray methods except in very rare cases with widespread metastases. Even then, the local lesion is not evident. When the source material consists of surgical specimens, the appendix is by far the most common site. Diffenbaugh and Anderson (13) reported metastases in 29 of 825 appendiceal carcinoids, an incidence of 3.5 per cent. Carcinoids of the Stomach The previously cited review of 509 collected carcinoids from the literature (9) showed 9 in the stomach, an incidence of 2 per cent. Lattes and Grossi (14) report 5 cases of primary involvement of the stomach from the Columbia Presbyterian Medical Center from 1936 to 1955. During this period, the number of gastric tumors found was as follows: Carcinoma, 1,235; leiomyoma, 38; leiomyosarcoma, 17; lymphosarcoma, 34; adenoma, 31; carcinoid, 5. Recently, Pochaczevsky and Sherman (15) described the roentgen appearances of gastric carcinoids based on 3 new cases and 59 previously published.