Carcinoid Syndrome
Overview
Plain-Language Overview
Carcinoid Syndrome is a condition caused by certain types of tumors called carcinoid tumors that usually start in the digestive system or lungs. These tumors release chemicals like serotonin into the bloodstream, which can affect many parts of the body. The main symptoms include flushing of the skin, diarrhea, and wheezing or difficulty breathing. These symptoms happen because the chemicals cause changes in blood vessels and the intestines. The syndrome mainly affects the digestive and respiratory systems. It can also lead to heart problems if untreated. Understanding these symptoms helps identify the syndrome early.
Clinical Definition
Carcinoid Syndrome is a paraneoplastic syndrome caused by the systemic release of vasoactive substances, primarily serotonin, from neuroendocrine tumors known as carcinoid tumors. These tumors most commonly arise from the small intestine, appendix, or bronchopulmonary system. The syndrome manifests when these substances bypass hepatic metabolism, typically due to liver metastases, leading to symptoms such as cutaneous flushing, secretory diarrhea, bronchospasm, and right-sided valvular heart disease. The pathophysiology involves excessive serotonin and other peptides causing vasodilation and smooth muscle contraction. Diagnosis and management are critical due to potential complications like carcinoid heart disease and malnutrition.