How often does carcinoid syndrome occur in patients with carcinoid tumor?
Carcinoid syndrome is a syndrome that clinically presents with cutaneous flushing, sweating, bronchospasm, colicky abdominal pain, diarrhea, and right-sided cardiac valvular fibrosis and occurs in less than 10% of patients with carcinoid tumor. The syndrome is due to the secretion of vasoactive substances (e.g., serotonin) by the tumor and most commonly occurs in patients with hepatic metastases, as the secreted substances are then able to enter the systemic circulation without undergoing hepatic degradation.
