Snapshot A 42-year-old man presents to the clinic with complaint of watery diarrhea for the past four months. He states that he has not seen any blood in his stool. Upon further questioning, he states that he has also experienced intermittent abdominal pain and asthma attacks. On physical examination, the patient's face and neck appears as seen in the image. Introduction Overview carcinoid syndrome is a rare syndrome that is caused by the metastasis of carcinoid tumors that secrete high levels of serotonin (5-HT) login to view 1 more bullet Epidemiology Incidence rare, 1-2 cases per 100,000 individuals Demographics most frequently in patients 50-70 years ETIOLOGY Pathophysiology metastasis of carcinoid tumors that produce serotonin login to view 4 more bullets Associated conditions medical conditions login to view 2 more bullets Presentation Symptoms common symptoms login to view 5 more bullets Physical exam erythema pellagra skin lesions wheezing hepatomegaly from metastases pulmonary systolic and diastolic heart murmur login to view 3 more bullets Imaging CT indication login to view 2 more bullets In-111 octreotide scan indication login to view 1 more bullet Studies Labs measurement of urinary excretion of 5-HIAA login to view 3 more bullets Differential VIPoma key distinguishing factor login to view 5 more bullets Treatment Surgical surgical resection of tumor login to view 3 more bullets Medical octreotide or other somatostatin analog login to view 2 more bullets Complications Carcinoid heart disease incidence login to view 1 more bullet risk factors login to view 1 more bullet treatment login to view 1 more bullet