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

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Flashcards in Neoplasia III: Carcinoid, GIST, Lymphoma (aka zebra lecture) Deck (38):
1

Pathophys of gastric carcinoid tumors?

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

2

Micro morphology of gastric carcinoid tumors?

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

3

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

Zollinger-Ellison syndrome
slow-growing
mets uncommon

4

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

aggressive
many mets at dx
carcinoid syndrome

5

How do ileal tumors present?

with carcinoid syndrome

(flushing, bronchospasm, incr motility, R cardiac valve thickening)

6

Most important prognostic factor for GI carcinoid?

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

7

What labs are associated with Z-E syndrome?

Fasting gastrin level >1000 pg/ml

8

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

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

positive = gastrin incr by >200

9

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

If mets?

Surgical resection
Medical management (PPI, LA somatostatin)

resection
doxorubicin/streptozocin

10

Epidemiology of Intestinal Neuroendocrine Tumor (Carcinoid)?

Typically in late middle-aged patients
(~6th decade)

11

Most common location of Intestinal Neuroendocrine Tumor (Carcinoid)?

Ileum and appendix

**often at multiple sites

12

Most frequent symptom of Intestinal Neuroendocrine Tumor (Carcinoid)?

Abdominal pain

13

Common complication of Intestinal Neuroendocrine Tumor (Carcinoid)?

Intermittent obstruction

14

Most common neoplasm of appendix?

Intestinal Neuroendocrine Tumor (Carcinoid)

15

What is carcinoid syndrome?

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

**caused by vasoactive polypeptides, serotonin

16

How do you diagnose carcinoid syndrome?

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

17

Colorectal NET:
How do they present in colon? In rectum?

most commonly presents as large mass in right colon

rectum = usually only found incidentally

18

What type of cells are present in GIST?

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

19

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

Tumor size
Mitotic activity
Necrosis

**GIST should be "regarded as malignant"

20

GIST can be stained for:

CD177 (via antibodies)

21

Epidemiology of GIST?

Most common location of GIST?

older adults

stomach and small intestine

22

GIST are thought to derive from or differentiate toward:

interstitial cells of Cajal
(GI PM cells that form the interface between the autonomic innervation and smooth muscle cells of the gut)

23

Most GIST have mutations in:

KIT transmembrane receptor TK

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

24

GIST: Presentation?

GI bleeding
abd mass
abd pain

25

GIST: Method of detection?

CT
Endoscopic US-guided fine needle aspiration

26

Trx for GIST?

srx

imatinib (TKI), if mets

27

What causes Post-Transplant Lymphoproliferative Disorder?

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

28

What may control Post-Transplant Lymphoproliferative Disorder?

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

29

What are the 2 types of GI lymphomas?

~ 50% = low grade mucosa-associated lymphoid tissue “MALTomas”

~50% = aggressive diffuse large B-cell lymphomas

30

Epidemiology of GI lymphoma?

older adults

31

GI lymphoma is associated with what conditions?

H pylori
AI disease
Celiac
immuno-deficiency/-suppression

32

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

large-cell lymphomas, EBV positive and consistently overexpress p53

33

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

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

34

Gastric lymphomas are more frequent in patients with chronic:

inflmm, which occurs with chronic inf w/ H pylori

35

Gastric lymphomas are likely to regress if:

H pylori is eradicated

36

Micropath of MALTomas?

abundant plasma cell-like features

37

Trx for MALTomas?
Prognosis?

antibiotics

good!

38

Trx for non-MALT lymphomas of GIT?
Prognosis?

radiation and / or chemotherapy

bad