carcinoid tumors

Question 1

what are carcinoid tumors?

Answer 1

tumors of neuroendocrine cells (kulchitsky cells) arising from GI tract esp appendix (or lungs, pancreas) and secrete hormones, specifically serotonin

Question 2

pathophysiology of carcinoid? why some asymptomatic and some not?

Answer 2

most tumors are asymptomatic bcz serotonin is metabolized in the liver when it drains by portal vein.

in cases where the tumor metastasizes to the liver or occurs outside the GI tract, it will become symptomatic, causing carcinoid syndrome and carcinoid heart disease

Question 3

what are carcinoid syndrome and carcinoid heart disease?

Answer 3

carcinoid syndrome: diarrhea and abdomen cramps, flushing, wheeze and SOB (asthma-like attacks), palpitations

carcinoid heart disease: endocardial fibrosis of the right heart (left heart is protected bcz serotonin is inactivated by the lungs), tricuspid insufficiency/ pulmonary stenosis, RHF

Question 4

diagnosis?

Answer 4

-fasting 5-HIAA levels (metabolite of serotonin)
-24-urine collection (high 5-HIAA)

CT abdomen, biopsy

Question 5

treatment?

Answer 5

operable: surgical resection depending on location

non operable: pharmacotherapy
-somatostatin drugs (octreotide) for symptomatic relief
-telotristat as adjunct if diarrhea not controlled with somatostatin