Neoplasia III: Carcinoid, GIST, Lymphoma (aka zebra lecture)

Question 1

Pathophys of gastric carcinoid tumors?

Answer 1

1. Chronic gastritis or Gastric acid suppression
2. Hypergastrinemia compensatory response
3. Gastric diffuse neuroendocrine hyperplasia
   =Tumor

Question 2

Micro morphology of gastric carcinoid tumors?

Answer 2

islands or sheets of uniform cohesive cells, often (+) for NE markers such as chromogranin

Question 3

What other characteristics/presentations are associated with gastric carcinoid tumors that secrete gastrin?

Answer 3

Zollinger-Ellison syndrome
slow-growing
mets uncommon

Question 4

What other characteristics/presentations are associated with gastric carcinoid tumors that DON”T secrete gastrin?

Answer 4

aggressive
many mets at dx
carcinoid syndrome

Question 5

How do ileal tumors present?

Answer 5

with carcinoid syndrome

flushing, bronchospasm, incr motility, R cardiac valve thickening

Question 6

Most important prognostic factor for GI carcinoid?

Answer 6

location:

1. foregut–rarely met, cured by srx
2. midgut–multiple, aggressive
3. hindgut–found incidentally

Question 7

What labs are associated with Z-E syndrome?

Answer 7

Fasting gastrin level >1000 pg/ml

Question 8

What diagnostic tests are used to dx Z-E syndrome?

Answer 8

Secretin stimulation test (measure gastrin levels incrementally after IV secretin administered)

positive = gastrin incr by >200

Question 9

Treatment of Zollinger-Ellison syndrome, if solitary + non-met?

If mets?

Answer 9

Surgical resection
Medical management (PPI, LA somatostatin)

resection
doxorubicin/streptozocin

Question 10

Epidemiology of Intestinal Neuroendocrine Tumor (Carcinoid)?

Answer 10

Typically in late middle-aged patients

~6th decade

Question 11

Most common location of Intestinal Neuroendocrine Tumor (Carcinoid)?

Answer 11

Ileum and appendix

**often at multiple sites

Question 12

Most frequent symptom of Intestinal Neuroendocrine Tumor (Carcinoid)?

Answer 12

Abdominal pain

Question 13

Common complication of Intestinal Neuroendocrine Tumor (Carcinoid)?

Answer 13

Intermittent obstruction

Question 14

Most common neoplasm of appendix?

Answer 14

Intestinal Neuroendocrine Tumor (Carcinoid)

Question 15

What is carcinoid syndrome?

Answer 15

Episodes of: 
flushing (95%)
diarrhea, 
wheezing
colicky abdominal pain
Right heart endocardial fibrosis (50%)

**caused by vasoactive polypeptides, serotonin

Question 16

How do you diagnose carcinoid syndrome?

Answer 16

High urine 5-hydroxyindole acetic acid (5-HIAA) (but limited sensitivity and specificity)

Question 17

Colorectal NET:

How do they present in colon? In rectum?

Answer 17

most commonly presents as large mass in right colon

rectum = usually only found incidentally

Question 18

What type of cells are present in GIST?

Answer 18

spindle, epithelioid or occasionally pleomorphic mesenchymal cells that often express the KIT (CD117) protein

Question 19

The best predictor of biological behavior of GISTs is a combination of:

Answer 19

Tumor size
Mitotic activity
Necrosis

**GIST should be “regarded as malignant”

Question 20

GIST can be stained for:

Answer 20

CD177 (via antibodies)

Question 21

Epidemiology of GIST?

Most common location of GIST?

Answer 21

older adults

stomach and small intestine

Question 22

GIST are thought to derive from or differentiate toward:

Answer 22

interstitial cells of Cajal

GI PM cells that form the interface between the autonomic innervation and smooth muscle cells of the gut

Question 23

Most GIST have mutations in:

Answer 23

KIT transmembrane receptor TK

**activates as oncogene, w/ (+) immunostain for CD117

Question 24

GIST: Presentation?

Answer 24

GI bleeding
abd mass
abd pain

Question 25

GIST: Method of detection?

Answer 25

CT | Endoscopic US-guided fine needle aspiration

Question 26

Trx for GIST?

Answer 26

srx imatinib (TKI), if mets

Question 27

What causes Post-Transplant Lymphoproliferative Disorder?

Answer 27

Immunosuppression can allow B cells infected with Epstein-Barr virus to proliferate in an uncontrolled manner.

Question 28

What may control Post-Transplant Lymphoproliferative Disorder?

Answer 28

If the immunosuppression can be safely decreased, sometimes the proliferation will come under control, sometimes not.

Question 29

What are the 2 types of GI lymphomas?

Answer 29

~ 50% = low grade mucosa-associated lymphoid tissue “MALTomas” ~50% = aggressive diffuse large B-cell lymphomas

Question 30

Epidemiology of GI lymphoma?

Answer 30

older adults

Question 31

GI lymphoma is associated with what conditions?

Answer 31

H pylori AI disease Celiac immuno-deficiency/-suppression

Question 32

What type of lymphoma is often present in immunocompr or immunosuppressed patients?

Answer 32

large-cell lymphomas, EBV positive and consistently overexpress p53

Question 33

What type of lymphoma often develops in patients with refractory gluten disease?

Answer 33

T-cell lymphomas (Enteropathy-Associated T-cell Lymphoma) most often in the small bowel

Question 34

Gastric lymphomas are more frequent in patients with chronic:

Answer 34

inflmm, which occurs with chronic inf w/ H pylori

Question 35

Gastric lymphomas are likely to regress if:

Answer 35

H pylori is eradicated

Question 36

Micropath of MALTomas?

Answer 36

abundant plasma cell-like features

Question 37

Trx for MALTomas? | Prognosis?

Answer 37

antibiotics good!

Question 38

Trx for non-MALT lymphomas of GIT? | Prognosis?

Answer 38

radiation and / or chemotherapy bad