Carcinoid Syndrome

Carcinoid is the most common GI endocrine tumor.

15 cases in 1 million population per y.

Seen in fewer than 20% of pts with carcinoid.

Urinalysis for 5-HIAA and serotonin levels

Platelet serotonin levels

Serum chromogranin A

CT scan and MRI

Octreoscan and MIBG

Associated with pt’s ability to tolerate abrupt hemodynamic change and/or bronchospasm

Abrupt Htn or hypotension with stress

Right-sided valvular heart disease

Electrolyte disturbances (due to intestinal secretion of sodium, potassium, and water)

Bronchospasm

Endocrinologically active tumor from GI mucosa

May release histamine-like substances, leading to hypotension and bronchospasm, or may release serotonin, leading to hypertensive reactions (and hypovolemia)

Commonly found in ileum or rectum; less so in pancreas and lung

Systemically active when metastatic to liver, or when released substances avoid metabolism by liver (carcinoid syndrome)

Left-sided cardiac disease in 10% of pts if there is a pulmonary carcinoid