CH10 - Gastrointestinal Pathology Flashcards Preview

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Flashcards in CH10 - Gastrointestinal Pathology Deck (345)
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301

How is screening for polyps performed?

by colonoscopy and testing for fecal occult blood

302

How do polyps present clinically?

they are usually clinically silent, but can bleed.

303

What is the goal in term of polyps?

it is to remove adenomatous polyps before progression to carcinoma

304

On colonoscopy can you tell the difference between hyperplastic and adenomatous polyps?

No they look identical. Hence, all polyps are removed and examined microscopically

305

With polyps what is the risk for progression from adenoma to carcinoma related to?

size > 2 cm, sessile growth, and villous histology.

306

What is familial adenomatous polyposis?

(FAP)Autosomal dominant disorder characterized by 100s to 1000s of adenomatous colonic polyps

307

What is familial adenomatous polyposis (FAP) due to?

inherited APC mutation (chromosome 5); increases propensity to develop adenomatous polyps throughout colon and rectum

308

How is familial adenomatous polyposis treated?

Colon and rectum are removed prophylacticly ; otherwise, almost all patients develop carcinoma by 40 years of age.

309

What is gardner syndrome?

it is FAP with fibromatosis and osteomas

310

What is fibromatosis?

it is a non-neoplastic proliferation of fibroblasts

311

Where does fibromatosis arise?

in retroperitoneum (desmoid) and locally destroys tissue

312

What is Osteoma?

it is a benign tumor of bone that usually arises in the skull

313

What is Turcot syndrome?

it is FAP with CNS tumors (medulloblastoma and glial tumors)

314

What is a juvenile polyp?

Sporadic, hamartomatous (benign) polyp that arises in children (< 5 years)

315

How does juvenile polyp usually present?

as a solitary rectal polyp that prolapses and bleeds

316

What is juvenile polyposis characterized by?

multiple juvenile polyps in the stomach and colon; large numbers of juvenile polyps increase the risk of progression to carcinoma.

317

What is peutz-jeghers syndrome?

Hamartomatous (benign) polyp throughout GI tract and mucocutaneous hyperpigmentation (freckle-like spots) on lips, oral mucosa, and genital skin; autosomal dominant disorder

318

In Peutz-Jeghers Syndrome what is there an increased risk for?

colorectal, breast, and gynecologic cancer

319

What is colorectoal carcinoma?

Carcinoma arising from colonic or rectal mucosa

320

What is the 3rd most common site of cancer?

Colorectal carcinoma

321

What is the 3rd most common cause of cancer-related death?

Colorectal carcinoma

322

What is the peak incidence for colorectal carcinoma?

it is 60-70 years of age

323

What does colorectal carcinoma most commonly arise from?

adenoma-carcinoma sequence

324

For colorectal carcinoma what is a second important molecular pathway?

the microsatellite instability (MSI) pathway

325

What are microsatellites in the MSI pathway?

they are repeating sequences of noncoding DNA; integrity of the sequence (stability) is maintained during cell division.

326

What does instability in the microsatellite instability pathway indicate?

defective DNA copy mechanisms (eg. DNA mismatch repair enzymes).

327

What is HNPCC

Hereditary non polyposis colorectal carcinoma

328

What is HNPCC due to?

Inherited mutations in DNA mismatch repair enzymes.

329

With HNPCC what is there an increased risk for?

colorectal, ovarian, and endometrial carcinoma

330

Where does colorectal carcinoma arise?

de novo (not from adenomatous polyps) at a relatively early age; usually right-sided