GI Polyps and Carcinoma

Question 1

Polyp comes from the Greek for ___________.

Answer 1

morbid excrescence

Question 2

True or false: adenomas don’t need to be worried about.

Answer 2

False. They can be precursors to adenocarcinomas.

Question 3

The two main categories of histologic structure that polyps can resemble are ___________.

Answer 3

villous or tubular

Question 4

There are three kinds of non-neoplastic polyps: _______________.

Answer 4

inflammatory, hamartomatous, and hyperplastic

Question 5

_____________ polyps form from repeated injuries and healings.

Answer 5

Inflammatory

Question 6

What are hamartomas?

Answer 6

Non-neoplastic overgrowth of normal, mature tissue where it typically occurs

Question 7

True or false: hamartomas can present with or without non-GI symptoms and can portend cancer.

Answer 7

True. Syndromic hamartomas (Peutz-Jeghers) increase risk of GI carcinoma.

Question 8

____________ polyps are flat, nubby little lesions that present with a serrated appearance on histologic exam.

Answer 8

Hyperplastic

Question 9

In terms of nuclei, how will low-grade dysplasia and high-grade dysplasia differ?

Answer 9

Low-grade: pencil-shaped nuclei still roughly in line, but larger and darker than normal cells

High-grade: wildly different nuclei with no tendency to orient in any way toward the apical side

Question 10

Most colorectal cancer is sporadic or genetic?

Answer 10

Sporadic

Question 11

Microsatellite instability results from failure of which system?

Answer 11

The mismatch-repair system

Question 12

Beta-catenin is the activating signal for the _______ pathway.

Answer 12

Wnt

Question 13

Describe the Wnt pathway.

Answer 13

Beta-catenin is a transcription factor for growth proteins. APC is a scaffold protein that works to destroy beta-catenin (which it does statically). Wnt is a surface receptor. When it is stimulated, it activates a pathway that inhibits APC and allows beta-catenin to go free.

Question 14

What percent of colon cancer is due to FAP?

Answer 14

5%

Question 15

Lynch syndrome tends to appear on the ________ side.

Answer 15

right

Question 16

Inflammatory polyps often present in the ______________.

Answer 16

rectum

Question 17

Peutz-Jeghers syndrome often presents with what weird extra-intestinal symptom?

Answer 17

Mucocutaneous pigmentation (of the gums)

Question 18

True or false: all serrated polyps are benign.

Answer 18

False. Sessile serrated adenomas are pre-malignant.

Question 19

The serrated part occurs in the ______________.

Answer 19

crypts

Question 20

Adenomas are present in nearly _________ percent of adults by age 50.

Answer 20

50

Question 21

Polyps represent an increase in ______________.

Answer 21

the size of the proliferating compartment

Question 22

What two drugs can treat wild-type KRAS CRCs?

Answer 22

Cetuximab (which blocks the EGFR receptor that signals through the KRAS pathway) and FOLFOX

Question 23

What is the difference between T2 and T3?

Answer 23

T2 is invasion into the muscularis propria, and T3 is invasion into serosa/adventitia beyond the muscularis propria.