Internal Medicine

0521779407-C01 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:53

274 Carcinoid

■Rectal carcinoids: abdominal cramping and changes in bowel habits

*Note: rectal carcinoids do not cause carcinoid syndrome

Carcinoid Syndrome

■Flushing sensation lasting 2–5 minutes with warmth and erythema

of upper body, head and neck; often spontaneous; sometimes pre-

cipitated by stress, alcohol, cheeses

■Diarrhea up to 30 watery stools/day, often with crampy abdominal

pain

■Wheezing or asthma

■Cardiac manifestations: endocardial fibrosis predominantly of right

ventricle, causing tricuspid regurgitation, and less commonly pul-

monic stenosis.

tests

Basic Laboratory Tests

■elevated 24 h urine for 5-HIAA (75% sensitive and 100% specific for

carcinoid syndrome)

■elevated platelet 5-HIAA (more sensitive in combination with urinary

5-HIAA)

Other Tests

■plasma chromagranin A and B (not specific, can occur in patients

with pancreatic endocrine tumors)

■plasma HCG (elevated in 28% pts with carcinoid)

Radiographic Tests

■Octreotide scan (somatostatin receptor scintigraphy)

■I-MIBG

■Biphasic CT scan: for determining stage of disease, particularly to

determine if liver metastases present

Pathology

■although elevated urinary 5-HIAA pathognomonic, biopsy should

always be obtained for confirmation (and exclude other poorly dif-

ferentiated neuroendocrine tumors)

differential diagnosis

■Any tumor located in stomach, small bowel or rectum – the usual

sites of carcinoid tumors