GI Neoplasia III: Carcinoid/GIST/Lymphomas: Tombazzi

Question 1

Describe the 3 types of carcinoid tumors. 
Relative frequencies. 
Prognosis.
Mets
Clinical presentation
Other dz associations.

Answer 1

Types I and II most frequent (80%)
Type I- good prognosis, hypergastrinemia (antral origin)
Type II- some w/ mets. Gastrinoma (tumor outside stomach producing gastrin)
Type III- many w/ mets at Dx, aggressive. Not associated w/ hypergastrinemia.
Presentation: many asymptomatic, abd. pain, intermittent obstruction can occur.
Dz assoc: endocrine cell hyperplasia, autoimmune chronic atrophic gastritis, MEN-I, Z-E syndrome.

Question 2

Describe the histology of neuroendocrine tumors.

Answer 2

Packets/nests of small, round cells that display salt and pepper chromatin. All neuroendocrine tumors looks the same, histologically, regardless of origin.

Question 3

Most important prognostic factor for GI carcinoid tumors is:
Discuss the prognoses relative to this factor.

Answer 3

Location
Foregut (prox. to jejunum) rarely metastasize. Resection curative.
Midgut (jejunum, ileum) are often multiple and tend to be aggressive.
Hindgut (cecum, colorectum) found incidentally.

Question 4

Describe the serological profile of autoimmune gastritis.

Answer 4

Abs to parietal cells (H+/K+ATPase, intrinsic factor)

Question 5

Tx of Type I carcinoid tumor of antrum?

Answer 5

Remove antrum- curative, treats gastrinemia.

Question 6

What immunostains are positive in Type II carcinoid tumor?

Answer 6

Chromogranin, synaptophysin, and CD56

Question 7

Discuss the clinical presentation of carcinoid syndrome.

Answer 7

Episodes of cutaneous flushing, sweating, bronchospasm, colicky abdominal pain, diarrhea.
Right heart endocardial/valvular fibrosis (50%)
Pts can be overwhelmed by mass effect and hormones secreted into non-portal circulation (vasoactive peptides, serotonin, histamines)

Question 8

What hormone do you expect to be highly elevated in Zollinger-Ellison (Z-E) syndrome?
How do you Dx Z-E using levels of this hormone?

Answer 8

:: Gastrin (>2000 pg/ml) w/ gastric pH 200 pg/ml is Dx. 83% sensitivity, 100% specificity.

Question 9

Clinical presentation of Z-E syndrome:

Answer 9

Complicated peptic ulcer dz (secondary to excess gastric acid, thanks to excess gastrin release), diarrhea, abd. pain, weight loss, other.

Question 10

How do you treat Z-E syndrome?

Answer 10

Surgical resection for solitary, non met. dz
Medical- high dose PPI, long acting octreotide
For mets: chemo, resection, embolization, radioablation, orthotopic liver transplant.

Question 11

Two classic causes of hypertrophic gastritis:

Answer 11

Menetrier dz and Z-E syndrome

Menetrier- characteristic enlargement of gastric rugae in body and fundus (antrum not involved).
Z-E- Doubling of oxyntic mucosal thickness due to x5 number of parietal cells.

Question 12

Describe the gastrointestinal stromal tumor (GIST).

Answer 12

Most common submucosal tumor of stomach.
From benign to very aggressive.
Behaves depending on size and histo
Most common manifestations: incidentally found GI bleeding, abd. mass, abd. pain.

Question 13

Describe GIST histologically.

Answer 13

Arise from interstitial cells of Cajal (pacemaker cells)

Spindle-shaped or epithelioid, mesenchymal tumors.

Question 14

Describe the mutation most commonly causing GIST.

Answer 14

95% of GIST pos. for RTK C-kit mutation, also DOG1

Question 15

What is Carney triad?

Answer 15

non-hereditary syndrome of unknown etiology seen primarily in young females that includes:

• Gastric GIST
• Paraganglioma (extra-adrenal pheochromocytoma)
• Pulm. chondroma

Question 16

Tx for GIST:

Answer 16

Resection for local

RTK inhibitor for mets.

Question 17

Tell me about GI lymphoma. 
Where is it found?
Hodgkin or non-hodgkin?
B or T cells?
Presentation?
Dz associations?

Answer 17

Found in stomach and small bowel
Non-Hodgkin
B-cells
Same as adenocarcinoma. Epigastric pain, anorexia, weight loss, n/v, bleeding, early satiety.
H. pylori can cause MALT
Post-transplant lymphoproliferative due to Epstein-Barr Virus
Immunoproliferative small intestinal dz: malabsorption and Ig
Enteropathy assoc. T-Cell Lymphoma (EATCL): presents like celiac dz, but refractory to dietary changes.