Carcinoid syndrome is a constellation, collection, or group of symptoms experienced by a subset of people who have a neuroendocrine tumor.
The diagnosis of carcinoid syndrome is complicated by the fact that common conditions, such as irritable bowel syndrome and severe allergic reactions, can cause symptoms similar to those of carcinoid syndrome.
To make a carcinoid syndrome diagnosis, a doctor will likely begin by assessing your symptoms and ruling out or excluding other conditions with similar presentations. The process of considering other conditions that may be responsible for your symptoms is called a “differential diagnosis.”
If you have not been diagnosed with a neuroendocrine tumor, initial tests involve screening for biochemical markers of neuroendocrine tumors, followed by attempts to localize the tumor by using imaging (MRI, CT, scintigraphy) and/or endoscopic tests.1