Carcinoid Tumors

Question 1

What is a carcinoid tumor?

Answer 1

Tumor arising from neuroendocrine cells (Kulchitsky cells).

Secretes serotonin.

Question 2

Why is a carcinoid tumor called “carcinoid”?

Answer 2

A carcinoid resembles a carcinoma but is clinically and histologically less aggressive than most GI carcinomas

Question 3

How can you remember that Kulchitsky cells are found in carcinoid tumors?

Answer 3

KUL CAR

Question 4

What are the common sites for carcinoid tumors?

Answer 4

AIR:
Appendix, Ileum, Rectum
Also bronchus, jejunum, stomach, duodenum, colon, ovary, testicle, pancreas, thymus

Question 5

What are the signs and symptoms of a carcinoid tumor?

Answer 5

Depends on the location (most cases are asymptomatic).
SBO, abdominal pain, bleeding, weight loss, diaphoresis, pellagra skin changes, intussusception, carcinoid syndrome, wheezing

Question 6

Why SBO with carcinoid?

Answer 6

Severe mesenteric fibrosis

Question 7

What are the pellagra-like symptoms of a carcinoid tumor?

Answer 7

1. Dermatitis
2. Diarrhea
3. Dementia

Question 8

What causes pellagra in carcinoid patients?

Answer 8

Decreased niacin production

Question 9

What is carcinoid syndrome?

Answer 9

Syndrome of symptoms caused by release of substances from a carcinoid tumor

Question 10

What are the symptoms of carcinoid syndrome?

Answer 10

B FDR:

Bronchospasm, Flushing (skin), Diarrhea, Right-sided heart failure (from valve failure)

Question 11

Why does right-sided heart failure develop but not left-sided heart failure in carcinoid syndrome?

Answer 11

Lungs act as a filter, thus the left heart doesn’t see all the vasoactive compounds

Question 12

What is the incidence of carcinoid syndrome in patients with a carcinoid tumor?

Answer 12

10%

Question 13

What released substances cause carcinoid syndrome?

Answer 13

Serotonin and vasoactive peptides

Question 14

What is the medical treatment for carcinoid syndrome?

Answer 14

Octreotide IV

Question 15

What is the medical treatment of diarrhea alone in carcinoid syndrome?

Answer 15

Odansetron (Zofran)

Question 16

How does the liver prevent carcinoid syndrome?

Answer 16

By degradation of serotonin and the other vasoactive peptides when the tumor drains into the portal vein

Question 17

Why does carcinoid syndrome occur in some tumors and not in others?

Answer 17

Occurs when venous drainage from the tumor gains access to the systemic circulation by avoiding hepatic degradation of the vasoactive substances

Question 18

What tumors can produce carcinoid syndrome?

Answer 18

Liver metastases; retroperitoneal disease draining into paravertebral veins; primary tumor outside of GI tract, portal venous drainage, or both

Question 19

What does the liver break down serotonin into?

Answer 19

5-HIAA

Question 20

What percentage of patients with a carcinoid have an elevated urine 5-HIAA level?

Answer 20

50%

Question 21

What are the associated diagnostic lab findings with carcinoid tumor?

Answer 21

Elevated urine 5-HIAA as well as elevated urine and blood serotonin levels

Question 22

How do you remember 5-HIAA for carcinoid?

Answer 22

5-HIGH CAR pile up

Question 23

What stimulation test can often elevate serotonin levels and cause symptoms of carcinoid syndrome?

Answer 23

Pentagastrin stimulation

Question 24

How do you localize a GI carcinoid?

Answer 24

Barium enema; upper GI series with small bowel follow-through; colonoscopy; enteroscopy; enteroclysis; EGD; radiology tests

Question 25

What are the special radiologic (scintigraphy) localization tests for carcinoid tumors?

Answer 25

I-MIBG; In-octreotide; PET scan utilizing C-labeled HTP

Question 26

What is the surgical treatment for carcinoid tumor?

Answer 26

Excision of the primary tumor and single or feasible metastasis in the liver; chemotherapy for advanced disease

Question 27

What is the medical treatment for carcinoid tumor?

Answer 27

Palliation of the carcinoid syndrome (e.g. serotonin antagonists, somatostatin analog)

Question 28

How effective is octreotide in treating carcinoid syndrome?

Answer 28

It relieves diarrhea and flushing in more than 85% of cases and may shrink tumor in 10-20%

Question 29

What is a common anti-serotonin drug?

Answer 29

Cyproheptadine

Question 30

What is the overall prognosis for carcinoid tumor?

Answer 30

66% alive at 5 years

Question 31

What is the prognosis of patients with liver metastasis or carcinoid syndrome secondary to carcinoid tumor?

Answer 31

50% at 3 years

Question 32

What does a carcinoid tumor look like?

Answer 32

Usually intramural bowel mass.

Appears as yellowish tumor upon incision.

Question 33

For appendiceal carcinoid, when is a right hemicolectomy indicated vs. an appendectomy?

Answer 33

If the tumor is > 1.5 cm, right hemicolectomy is indicated.

If there are no signs of serosal or cecal involvement and tumor is < 1.5 cm, appendectomy should be performed.

Question 34

Which primary site of carcinoid tumor has the highest rate of metastasis?

Answer 34

Ileal primary tumor

Question 35

Can a carcinoid tumor be confirmed malignant by looking at the histology?

Answer 35

No, metastasis must be present to diagnose malignancy

Question 36

What is the correlation between carcinoid tumor size and malignancy potential?

Answer 36

Vast majority of tumors < 2 cm are benign.

In tumors > 2 cm, malignancy potential is significant.

Question 37

What treatments might you use for the patient with unresectable liver metastasis that is refractory to medical treatment?

Answer 37

Chemoembolization or radiofrequency ablation

Question 38

What are the overall survival rates for carcinoid tumors at 5 years? 10 years?

Answer 38

70%; 50%

Question 39

What are the side effects of colorectal carcinoid?

Answer 39

Most common side effect is rectal bleeding +/- vague abdominal pain or discomfort