Carcinoid tumors of the gastrointestinal tract.

The charts of 135 patients with gastrointestinal carcinoid tumors diagnosed over a 22-year period at 2 hospitals are reviewed and the clinical and pathological aspects discussed. Carcinoids occur most commonly in the appendix, jejunoileum, and rectum. Those smaller than 1 cm in diameter provide evidence of malignant potential only occasionally; lesions in the 1-1.9 cm range do this quite variably, and tumors 2 cm and larger are almost always invasive or metastatic or both. All gastrointestinal carcinoids except those of the appendix enlarge, invade, and metastasize predictably if given sufficient time. Most carcinoids except those of the rectum have already been adequately treated surgically when diagnosed by the pathologist. Local excision is effective treatment for noninvasive rectal carcinoids smaller than 2 cm in diameter, but those that have invaded or grown to 2 cm should undergo more radical resection. In general, gastrointestinal carcinoids carry better prognoses than do adenocarcinomata, and even in the presence of distant metastases long-term survival occurs in a significant number of patients. The frequent concomitance of associated malignant diseases accounts for as many or more deaths in these patients than the carcinoids themselves.