Final answer:
Carcinoid tumors associated with carcinoid syndrome typically originate in the gastrointestinal tract and often metastasize to the liver.
Step-by-step explanation:
The locations of tumors in carcinoid syndrome are typically found in the liver and gastrointestinal tract. Carcinoid tumors are a type of neuroendocrine tumor that originate most often in the small intestine, appendix, or rectum, but can also arise in other parts of the gastrointestinal tract. These tumors can release hormones into the bloodstream, leading to the symptoms associated with carcinoid syndrome. When such tumors metastasize, the liver is a common secondary site. This is in line with the tendency of certain cancer types to metastasize to particular organs, as different cancers have preferred sites of metastasis, such as the liver, lungs, bones, and brain.