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Caring for Carcinoid Foundation

Carcinoid Syndrome

Carcinoid Syndrome

Carcinoid tumors can secrete a variety of hormones which can cause many clinical symptoms such as flushing and diarrhea.  Symptoms occurring together may be classified as a syndrome.  Carcinoid Syndrome occurs in approximately 10% of individuals with carcinoid tumors and is most commonly found in individuals with midgut carcinoid tumors that have metastasized to the liver (Poncet, Faucheron, & Walter, 2010).  In midgut carcinoid tumors, carcinoid syndrome does not normally develop until the tumors have metastasized since the liver is able to break down the excess hormones produced by these tumors (Kulke, 2007).  However, once the tumors develop in the liver, the liver is no longer able to break down the excess hormones, and symptoms from them may occur.  Carcinoid tumors that develop outside of the midgut can cause carcinoid syndrome without liver metastases, but rarely do. 

Typical Carcinoid Syndrome

Typical Carcinoid Syndrome is the most common form of Carcinoid Syndrome and is most often caused by midgut carcinoids that have metastasized to the liver.  Excess serotonin is the hormone most frequently related to Carcinoid Syndrome.  The syndrome is characterized by brief episodes of flushing, diarrhea, cough, wheezing, shortness of breath, heart disease, and in rare cases, pellagra.  Flushing and diarrhea are the two main symptoms that are associated with Carcinoid Syndrome.  Diarrhea can be mild to severe which may lead to weight loss and life style changes.  The flushing may be light pink to a deep red and occurs in the face and in the nipple-line.  It may be triggered by stress, alcohol, exercise and certain types of foods.

Atypical Carcinoid Syndrome

Atypical Carcinoid Syndrome is rare and is associated with foregut carcinoid tumors.  It is characterized by extended episodes of flushing, headache, shortness of breath, and in rare cases, lacrimation (tears) (Tomassetti, Migliori, Lalli, Campana, Tomasetti, & Corinaldesi, 2001).  The flushing can be deep purple and last for hours. It may be followed by increased blood flood to the limbs (arms and legs) and to the trunk (chest, stomach and back).  This flush is not brought on by food (Tomassetti et al., 2001).

Carcinoid Crisis

Individuals with Carcinoid Syndrome can also experience Carcinoid Crisis which can occur spontaneously or be stress induced.  A Carcinoid Crisis can be a life-threatening event that requires careful monitoring.  Symptoms of a Carcinoid Crisis may include severe hypotension or hypertension, irregular and/or rapid heartbeat, wheezing, prolonged flushing, severe dyspnea (shortness of breath), and peripheral cyanosis (lack of oxygenated blood).


Kulke, M. H. (2007). Clinical Presentation and Management of Carcinoid Tumors.Hematology/Oncology Clinics of North America, 21, 433-455. Retrieved from:

Poncet, G., Faucheron, J., and Walter, T. (2010). Recent trends in the treatment of well-differentiated endocrine carcinoma to the small bowel. World Journal of Gastroenterology, 16(14), 1696-1706. Retrieved from:

Tomasseti, P., Migliori, M., Lalli, S., Campana, D., Tomassetti, V., Corinaldesi, R. (2001). Epidemiology, clinical features and diagnosis of gastroenteropancreatic endocrine tumours. Annals of Oncology, 12(2), S95-S99. Retrieved from: