Small Intestine and Colon Pathology 3

Question 1

Inflammatory Polyp associations

Answer 1

• -Solitary rectal ulcer syndrome
• -Ulcerative colitis
• -Crohn’s disease

Question 2

How do inflammatory polyps present?

Answer 2

Inflammatory, non-neoplastic process in GI tract

Question 3

Inflammatory pseudopolyps

Answer 3

In UC and CD. Represent inflamed and regenerating mucosa that projects above the level of surrounding mucosa (often ulcerated)

Question 4

Inflammatory pseudopolyp pathology

Answer 4

Mix of acute inflammation, dense mucosal lymphoplasmacytic infiltrate, distorted dilated crypts w/surface erosion, cryptitis, crypt abscesses

Question 5

Juvenile polyps (Retention polyps)

Answer 5

• -Can occur sporadically or as result of polyposis syndrome.
• -Most common type of polyp to occur in children

Question 6

Gene mutations associated with juvenile polyposis syndrome

Answer 6

SMAD4 and BMPRIA.

Question 7

Are ind. with juvenile polyposis syndrome at an increased risk for GI tract adenocarcinoma?

Answer 7

Yes.

Question 8

Where do retention polyps usually occur?

Answer 8

In colon (usually rectum). Usually solitary if spontaneous. Numerous polyps often seen in polyposis syndrome and may occur in stomach, small bowel, and colon

Question 9

Gross morphology of Juvenile (retention) polyps

Answer 9

–Rounded, smooth, unilobular w/erythematous cap of eroded tissue.

Question 10

Microscopic morphology of Juvenile (retention polyps)

Answer 10

• -Dilated, branched, mucin-filled crypts.
• -Crypt abscesses, neutrophils, and/or eosinophil collections may be present.
• -Surrounding stroma expanded w/many mixed inflammatory cells.

Question 11

Peutz-Jeghers polyps

Answer 11

• -Most common in small bowel
• -Seen in Peutz-Jeghers syndrome
• -Can present in childhood w/GI bleeding and intussusception
• -Increased risk of cancer

Question 12

Peutz Jeghers polyp morphology

Answer 12

–Arborizing (branching) smooth muscle pattern w/bland mucosal proliferation and are often pedunculated.

Question 13

Hyperplastic polyps

Answer 13

• -Small
• -Left colonic polyp
• -Most common type of adult polyp
• -Proliferative polyp w/o significant malignant potential

Question 14

Adenoma (adenomatous polyp)

Answer 14

• -Can occur anywhere
• -Benign, but can be precursor to adenocarcinoma.
• -Removed during colonoscopy to reduce risk of malignant colorectal adenocarcinoma

Question 15

Adenoma morphology

Answer 15

Dysplastic glandular proliferation or tubular or villous proliferation

Question 16

Sessile serrated polyp (adenoma)

Answer 16

• -Usually in R colon.

- -Can be precursor to adenocarcinoma

Question 17

Sessile serrated polyp morphology

Answer 17

• -Lack adenomatous epithelium
• -Prominent serration at all levels of the crypts, crypt dilation, horizontally shaped crypts, abundant goblet cells.
• -Crypt nuclei w/cytoplasmic eosinophilia, nuclear stratification, loss of cell polarity

Question 18

Peutz-Jeghers Syndrome

Answer 18

–Multiple polyps and mucocutaneous pigmentation

Question 19

What mutation can cause Peutz-Jeghers syndrome

Answer 19

Loss of function mutations in STK11 (tumor suppressor gene)–> increased risk of GI tract adenocarcinomas (and other cancers)

Question 20

Familial adenomatosis polyposis (FAP) mutation and inheritance

Answer 20

• -Autosomal dominant.

- -Mutations in APC tumor suppressor gene.

Question 21

Diagnosis of FAP

Answer 21

> 100 polyps and detection of germline mutations in APC gene

Question 22

Tx of FAP

Answer 22

Screening in adolescence followed by post-adolescent prophylactic colectomy

Question 23

FAP polyp characteristics

Answer 23

• -Develop large numbers in colon and rectum

- -Can get polyps in small bowel and stomach

Question 24

What types of cancer are individuals with FAP at increased risk of?

Answer 24

Colorectal adenocarcinoma (100%)
Upper GI tract adenocarcinoma (esp. at ampulla)

Question 25

Gardner’s syndrome

Answer 25

–In addition to FAP, get desmoid (fibrous) tumors inside peritoneal cavity, osteomas, epidermal cysts, dental abnormalities, thyroid tumors

Question 26

Lynch syndrome (HNPCC) mutations

Answer 26

Mutations in genes that encode enzymatic mismatch repair proteins. Inherit one defective allele and acquire another (mostly in microsatellite DNA)

Question 27

70-80% of patients w/FAP present with what?

Answer 27

Hypertrophy of pigmented retinal epithelium

Question 28

Lynch syndrome and risk of colorectal cancer

Answer 28

• -Don’t develop increased # of adenomas
• -When adenomas occur have risk of colon cancer development of 80-90%
• -Risk of small bowel carcinoma increased

Question 29

Turcot syndrome

Answer 29

Coexistence of hereditary colon cancer syndrome along with CNS tumors

Question 30

What tumor is common in Turcot syndrome with FAP? With HNPCC?

Answer 30

• -Medulloblastoma and FAP

- -Glioblastoma multiforme and HNPCC