Mehlman. Polyp conditions+colorectal 10-27 (1)

Question 1

Lynch syndrome (HNPCC).
Mismatch repair genes MSH2/6, MLH1, PMS2.

Answer 1

.

Question 2

Lynch syndrome (HNPCC). mutations cause what?

Answer 2

microsatellite instability.

Question 3

Lynch syndrome (HNPCC).
Hereditary non-polyposis colorectal cancer.

Question 4

Lynch syndrome (HNPCC). assoc with what cancer?

Answer 4

Its colonic polyps/cancer; also associated with gynecologic cancer.

Question 5

Lynch syndrome (HNPCC). when start colonoscopy?

Answer 5

Start colonoscopy at age 20-25, then do every 1-2 years.

Question 6

Familial Adenomatous Polyposis (FAP); chromosome 5; AD.

Answer 6

.

Question 7

FAP. Hundreds to thousands of polyps on colonoscopy; 100% cancer risk.

Answer 7

.

Question 8

FAP. when start colonoscopy?

Answer 8

Start colonoscopy at age 10-12 and do every 1-2 years. Then do prophylactic proctocolectomy at age 18 (on NBME).

Question 9

FAP + soft tissue (e.g., lipoma) or bone tumors (e.g., of the skull) = syndrome?

Answer 9

Gardner syndrome.

Question 10

FAP + CNS tumors = syndrome?

Answer 10

Turcot syndrome

Question 11

Peutz-Jeghers. definition?

Answer 11

Combo of perioral melanosis and HAMARTOMATOUS colonic polyps.

Question 12

Peutz-Jeghers. screening?

Answer 12

Start colonoscopy at age 8, then do every 1-2 years.

Question 13

Juvenile polyposis. Shows up on a 2CK NBME.

Answer 13

.

Question 14

Juvenile polyposis.

Q will tell you there’s a teenager (i.e., juvenile, LOL!) with intermittent bleeding
per rectum + colonoscopy shows scattered polyps + biopsy shows “dilated, cystic,
mucus-filled glands with abundant lamina propria and inflammatory infiltrates”
-> answer = juvenile polyposis.

Answer 14

Only question I’ve seen on it, but it’s on new 2CK NBME so I have to mention it.

Question 15

Hyperplastic polyps.

All you need to know is these are not pre-cancerous / have no dysplasia.

Answer 15

.

Question 16

Tubulovillous.

Dysplastic polyps that precede full-blown colorectal cancer are classically either tubular or villous, AND either pedunculated or sessile.

Answer 16

.

Question 17

Tubulovillous.
Villous vs tubular?

Answer 17

villous is worse

Question 18

Tubulovillous.
Sessile vs pedunculated?

Answer 18

Sessile is worse than pedunculated.

Question 19

Tubulovillous. the worst polyp?

Answer 19

Villous sessile

Question 20

Tubulovillous. the best polyp?

Answer 20

Tubular pedunculated

Question 21

Tubulovillous. Sessile means flat; pedunculated means “sticks out.”

Answer 21

.

Question 22

Tubulovillous.
Polyps can have mixed chacteristics and hence be tubulovillous

Answer 22

.

Question 23

Tubulovillous.
USMLE will give you a random 65-year-old with a polyp + show you a pic + ask you what it is answer = “tubular polyp.” Student freaks out and says, “Wait, we need to know polyp pics??” No. The big picture
concept is that older people who get colorectal cancer will have tubular, villous, or tubulovillous polyps as I just said. Wrong answers would be things like hamartomatous, juvenile, and hyperplastic. You can just eliminate to get there
without even knowing the image.

Answer 23

.

Question 24

Tubulovillous.
2CK wants you to know that patients with HISTORY of dysplastic polyps need
repeat colonoscopies every 2-5 years, depending on size/morphology of polyp(s).

Answer 24

.

Question 25

Colorectal.
first KRAS, then PTEN, then DCC, then TP53.

Answer 25

.

Question 26

Colorectal. If they tell you a colon cancer has metastasized and force you to choose a gene that’s mutated?

Answer 26

TP53 for p53 protein

Question 27

Colorectal. - If they tell you a polyp is seen and there is no evidence of invasion of the stalk, what mutation?

Answer 27

choose KRAS

Question 28

Colorectal. Can cause what complication in pelvis?

Answer 28

Can cause colovesicular fistulas, where a passageway develops between the GI tract and bladder, leading to UTIs and mixed enteric flora in the urine.

Question 29

Colorectal. Colovesicular fistulas are also assesed for diverticulosis.

Answer 29

This is also assessed for diverticulosis on 2CK and seems to be a new diagnosis USMLE likes. This could also be due to Crohn, in theory, but I haven’t seen it on NBMEs yet.

Question 30

Colorectal. what causes endocarditis?

Answer 30

Can cause Strep bovis endocarditis. Obscure, but rare point assessed on USMLE.