Path LI

Question 1

IBS vs IBD

Answer 1

IBS has no identifiable inflammation

Question 2

Angiodysplasia

Answer 2

• Abnormal venous dilation in mucosa/submucosa of LI
• A/S: Elderly w/ aortic valve disease
• S/S: Painless hematochezia

Question 3

LI Diverticula

Answer 3

• Usually False Diverticula
• ## Due to focal weakness in muscularis propria + increased intraluminal pressure

Question 4

LI Fistula

Answer 4

• Most common between bladder or Vagina

- Many due to diverticula

Question 5

LI Adenoma/polyps:

• What
• Histo
• Tx
• Genetics

Answer 5

• Benign precursor lesions of adenocarcinoma
• Histo: abnormal extension of mitotic zones into crypts; Epithelial dysplasia w/ elongated hyperchromic nuclei w/ pseudostratification
• Tx: Polyptectomy
• Genetics: AD; APC gene; Tx total colectomy

Question 6

Gardner Syndrome

Answer 6

• Adenopolyps
• Osteomas
• dental abnormalities
• Epidermal cysts
• desmoid + Thyroiod tumors

Question 7

Turcot Syndrome

Answer 7

FAP w/ Malignant CNS tumors

Question 8

Colorectal cancer Genetics

Answer 8

• APC TSG
• Protooncogene K-RAS
• Loss of TSG 18q21
• Aberrant overexpression COX-2
• Inactivation TSG p53

Question 9

nonobstructing polypoid, exophytic masses

Answer 9

carcinomas in the proximal colon

Question 10

circumferential lesions that produce “napkin ring” constrictions and luminal narrowing, sometimes to the point of obstruction

Answer 10

carcinomas in distal colon

Question 11

Metastatic Colorectal cancer

Answer 11

T1: invades submucosa
T2: Tumor infiltrates into muscularis propria
T3: Tumor invades through muscularis propria into subserosal tissue
T4: Tumor penetrates serosa or adjacent organs
N: Presence/absence of nodal metastasis
M: Indicates presence/absence of extranodal metastases

Question 12

2018 guidelines of the American Cancer Society

Answer 12

average risk of colorectal cancer start regular screening at age 45 by either a stool-based test every year (to detect occult blood in feces) or with an exam that looks at the colon and rectum (e.g., colonoscopy every 10 yearsis the gold standard).

Question 13

Most common Cancer of Anal Canal + genetics

Answer 13

• Squamous cell carcinoma

- HPV 16/18

Question 14

Appendiceal Tumors

Answer 14

• NE Tumors (Carcinoid) - Most common
• adenoma/adenocarcinoma
• mucinous cystadenoma/adenocarcinoma

Question 15

dissemination of mucus-producing tumor cells turn the peritoneal cavity into a gelatinous mass

Answer 15

pseudomyxoma peritonei

Question 16

• distended bowel

- ambulatory peritoneal dialysis

Answer 16

Sclerosing Peritonitis

Question 17

Peritoneal Neoplasms

Answer 17

• usually metastatic
• Mesothelioma
• desmoplastic small round cell tumor (EWS-WT1 gene fusion)