Carcinoid Tumors, C46 P301-305 Flashcards
What is a carcinoid tumor?
P301
Tumor arising from neuroendocrine cells
(APUDomas), a.k.a. Kulchitsky cells;
basically, a tumor that secretes serotonin
Why is it called “carcinoid”?
P301
Suffix “-oid” means “resembling”; thus,
carcinoid resembles a carcinoma but is
clinically and histologically less aggressive
than most GI carcinomas
How can you remember that
Kulchitsky cells are found in
carcinoid tumors?
P301
Think: “COOL CAR” or KULchitsky
CARcinoid
What is the incidence?
P301
Between 0.2% and 1.0% and about 25%
of all small bowel tumors
What are the common sites
of occurrence?
P301
“AIR”: 1. Appendix (most common) 2. Ileum 3. Rectum 4. Bronchus Other sites: jejunum, stomach, duodenum, colon, ovary, testicle, pancreas, thymus
What are the signs/
symptoms?
P301
Depends on location; most cases are asymptomatic; also SBO, abdominal pain, bleeding, weight loss, diaphoresis, pellagra skin changes, intussusception, carcinoid syndrome, wheezing
Why SBO with carcinoid?
P301
Classically = severe mesenteric fibrosis
What are the pellagra-like
symptoms?
P302
Think “3-D”:
- Dermatitis
- Diarrhea
- Dementia
What causes pellagra in
carcinoid patients?
P302
Decreased niacin production
What is carcinoid syndrome?
P302
Syndrome of symptoms caused by release
of substances from a carcinoid tumor
What are the symptoms of
carcinoid syndrome?
P302
Remember the acronym “B FDR”:
Bronchospasm
Flushing (skin) Diarrhea Right-sided heart failure (from valve failure)
What is a complete memory
aid for carcinoid?
P302 (picture)
Think: B FDR = CARcinoid, or “Be FDR
in a cool CAR” (COOL= KULchitsky cells)
Why does right-sided heart
failure develop but not
left-sided heart failure?
P302
Lungs act as a filter (just like the liver);
thus, the left heart doesn’t see all the
vasoactive compounds
What is the incidence of carcinoid SYNDROME in patients who have a carcinoid TUMOR? P302
≈10%
What released substances
cause carcinoid syndrome?
P302
Serotonin and vasoactive peptides
What is the medical treatment
for carcinoid syndrome?
P302
Octreotide IV
What is the medical
treatment of diarrhea alone?
P302
Odansetron (Zofran®)—serotonin
antagonist
How does the liver prevent
carcinoid syndrome?
P303
By degradation of serotonin and the
other vasoactive peptides when the
tumor drains into the portal vein
Why does carcinoid
syndrome occur in some
tumors and not in others?
P303
Occurs when venous drainage from the
tumor gains access to the systemic circulation
by avoiding hepatic degradation
of the vasoactive substances
What tumors can produce
carcinoid syndrome?
P303
Liver metastases
Retroperitoneal disease draining into
paravertebral veins
Primary tumor outside the GI tract,
portal venous drainage (e.g., ovary,
testicular, bronchus), or bothWhat does the liver break
down serotonin into?
P303
5-hydroxyindoleacetic acid (5-HIAA)
What percentage of patients
with a carcinoid have an
elevated urine 5-HIAA level?
P303
50%
What are the associated
diagnostic lab findings?
P303
Elevated urine 5-HIAA as well as
elevated urine and blood serotonin
levels
How do you remember
5-HIAA for carcinoid?
P303 (picture)
Think of a 5-HIGH CAR pile up =
5-HIAA CARcinoid
