Carcinoids, GISTs, and Lymphomas of the Colon and Rectum
Less common tumors of the colon and rectum include carcinoids, gastrointestinal stromal tumors, and gastrointestinal lymphomas. Carcinoids are of neuroectodermal origin and frequently secrete bioactive compounds such as serotonin and histamine. Carcinoids that have metastasized to the liver may cause systemic symptoms referred to the carcinoid syndrome. Treatment of carcinoid tumors is surgical resection; however, the type of resection is dependent on the size and location of the tumor. Adjuvant treatment of carcinoid tumors involves the use of somatostatin analogues. Gastrointestinal stromal tumors occur less frequently in the colon and rectum than in other organs of the intestinal tract but may be detected during endoscopic evaluation of the colon. Surgical treatment of GISTs also depends on the size and location of the tumor. Adjuvant treatment with imatinib (a tyrosine kinase inhibitor that blocks KIT activation) has been shown to reduce the risk of recurrence. The gastrointestinal tract is the most common site of extranodal lymphoma. Treatment typically involves a combination of surgical resection and systemic chemotherapy.
KeywordsCarcinoid Gastrointestinal stromal tumors (GISTs) Lymphoma Colorectum Treatment TNM staging
Transanal resection of a rectal GIST. (Courtesy of Rodrigo Perez, MD) (MP4 287260 kb)