Surgical management for carcinoid tumors of small bowel, appendix, colon, and rectum

Abstract

Carcinoid tumors occur most frequently in the gastrointestinal tract. Despite their ability to produce hormones, most of the midgut and hindgut carcinoids covered in this study are clinically silent, and the diagnosis is often not made before emergency surgery or evaluation for liver metastases. Because the rate of lymph node involvement and the prognosis of carcinoid tumors depend on their site and size, surgery refers to these two factors too. Lymph node metastases are most commonly found with small bowel carcinoids (20-45%), providing the rationale for an extended resection including the adjacent lymph node drainage area. Carcinoid tumors of the appendix < 1 cm in diameter rarely metastasize, simply requiring appendectomy for treatment. Lesions > 2 cm should be treated by right hemicolectomy because of their approximately 30% risk of lymph node metastases. Resection should always be done for carcinoid tumors of the colon resection as for adenocarcinomas. Rectal carcinoids < 2 cm rarely metastasize, directing the conclusion that for these smaller lesions local excision is sufficient; for lesions >2 cm a standard cancer resection should be performed provided distant metastases are absent. In general, the younger the patient or the larger the primary tumor, the more aggressive the treatment should be.