Lec 31

Question 1

What features of dysplasia in colorectal adenoma?

Answer 1

• elongated, darkly stained nuclei that are crowded/overlapping
• blurred distinction between cells; reduced or excessive mucin

Question 2

What is definition of a colorectal adenoma?

Answer 2

benign neoplasm consisting of dysplastic colorectal epithelium

Question 3

Are left or right sides polyps more likely to cause symptoms?

Answer 3

left sided b/c the lumen is smaller so more likely to cause obstruction; also blood in stool more visible from distal colon

Question 4

What is pedunculated vs sessile polyp?

Answer 4

pedunculated = permanent stalk created
sessile = broad based mound

Question 5

What percentage of CRCs are due to the adenoma-carcinoma sequence?

Answer 5

75%

Question 6

What is potential presentation of huge carpet-like adenoma?

Answer 6

water diarrhea, hypokalemia

Question 7

What is a hyperplastic polyp? histology?

Answer 7

tiny sessile polyp; usually in rectosigmoid [left] colon

has serrated elongated crypts that are not dysplastic

no malignant potential

Question 8

What mutation associated with sessile serrated polyp?

Answer 8

BRAF mutation

Question 9

Where are sessile serrated polyps usually located?

Answer 9

usually in right colon

Question 10

What is histology of cessile serrated polyp?

Answer 10

• serrated along entire length

- flat base resembling inverted letter T or L

Question 11

What is most important prognostic indicator of CRC?

Answer 11

tumor stage

Question 12

What are 2 parameters of tumor stage?

Answer 12

1. depth of tumor invasion

2. lymph node metastases

Question 13

What is a juvenile polyp?

Answer 13

occurs in children
often in recutm
spherical polyp; may cause rectal bleeding or obstruction

Question 14

What is juvenile polyposis syndrome?

Answer 14

autosomal dominant

have multiple juvenile polyps and increased risk of adenocarcinoma

Question 15

What is a hamartomatous polyp?

Answer 15

consists of lobules of non-dysplastic colonic epithelium surrounded by smooth muscle
not clinically significant as a single polpy

Question 16

What is peutz jeghers syndrome?

Answer 16

autosomal dominant; multiple non-moalignant hamartomas throughout GI tract + hyperpigmented mouth, lips, hands

increased risk of CRC

Question 17

Why do most CRCs have hard consistency?

Answer 17

desmoplastic reaction of tissue around the cancer

compare to adenomas = soft

Question 18

What are mucinous adenocarcinomas?

Answer 18

grossly gelatinous = cancer cells floating in pools of mucin

Question 19

Who gets mucinous adenocarcinoma of the colon?

Answer 19

very young and very old
IBD
lynch syndrome

Question 20

Is pronosis of mucinous adenocarcinoma better or owrse than other CRCs?

Answer 20

same

Question 21

Are microsatellite unstable cancers have better or worse prognsosis?

Answer 21

better prognosis

Question 22

What stain can you use for microsatellite unstable cancers?

Answer 22

CD3 immunostain –> MSI cancers often hve lymphocytes intermingled with tumor cells

Question 23

What is most common type of carcinoid tumor?

Answer 23

appendiceal carcinoid

Question 24

What is prognosis of appendiceal carcinoma?

Answer 24

good prognosis; rarely malignant

Question 25

What do you see on histology with carcinoid?

Answer 25

• nesting tumor pattern
• round nuclei
• speckled chromatin
• evenly spaced

Question 26

What is a mucinous cystadnoma?

Answer 26

usually benign mucus filled cyst in appendix

looks like villous adenoma on histology

Question 27

What is a complication of cystadenocarcinoma?

Answer 27

invades wall –> can get pesudomyxoma peritonei = mucus accumulates outside appendix and mixed wtih neoplastic cells

Question 28

What type of cancer is anal cancer usually?

Answer 28

squamous

Question 29

Where does anal cancer usually spread?

Answer 29

locally –> rectal sphincter, prostate, vagina

met –> iliac and inguinal lymph nodes