Ch. 17 Anus and Peritoneum

Question 1

What is the name of the site of transition from the postallantoic hindgut to the proctodeum?

Answer 1

Pectinate/dentate line

• Embryological division
• More importantly, transition from columnar epithelium to squamous epithelium

Question 2

What is the most likely cause of a perianal abscess/fistula?

Answer 2

Infection of anal gland where it opens into the crypt

Question 3

Metaplasia above the pectinate line can lead to what type of cancer?

Answer 3

Adenocarcinoma

Question 4

Metaplasia below the pectinate line can lead to what type of cancer?

Answer 4

SCC

Question 5

What virus is most likely associated with anal cancers?

Answer 5

HPV (same for oral SCC and cervical cancer)

All the places you can have sex= HPV

Question 6

65 y/o male presents with pain on defecation and reports bright red blood on toilet paper. What are your top 2 Ddx?

Answer 6

External Hemorrhoids (internal are painless)
Colon Cancer (ALWAYS screen for this age group + any GI bleeding)

Question 7

How can you treat internal hemorrhoids?

Answer 7

Intervened (sclerosing agent + rubber band) since they have visceral innervation and are painless

Question 8

Blood supplies to the rectum

Answer 8

Superior Rectal A: IMA
Middle Rectal A: Internal Iliac
Inferior Rectal A: Internal Pudendal

Question 9

What causes Hemorrhoids?

Answer 9

Persistent elevated venous pressure

Portal HTN= Butts, Guts, and Caputs (Medussa)

Question 10

A rectal approach can be used for evaluation of what 2 organs in a male patient?

Answer 10

Prostate

Appendix

Question 11

What position are majority of appendices found?

Answer 11

Retrocecal

Question 12

What are the 2 true diverticulums we have studied?

Answer 12

Meckel’s

the appendix!

Question 13

4 common Ddx for a CC of RLQ pain

Answer 13

Appendicitis
Meckels
Ectopic Pregnancy
Mesenteric Lymphadenitis (infectious enterocolitis)

Question 14

2 physical exams we could use to evaluate for appendicitis

Answer 14

McBurney Point Tenderness

Rovsing’s sign

Question 15

What is the most common cause of appendicitis?

Answer 15

Obstruction by fecaliths

Question 16

What nematode can cause appendicitis?

Answer 16

Pinworms (Anaerobes Vermicularis)

Question 17

Pseudomyxoma Peritonei

Answer 17

progressive intraperitoneal accumulation of ascites and mucous. Caused by a tumor of the appendix

Question 18

Leakage of bile or pancreatic enzymes that causes inflammation is termed:

Answer 18

Sterile Peritonitis

Question 19

What 2 populations does Spontaneous Bacterial Peritonitis develop in?

Answer 19

Cirrhotic patients with ascites

Children with nephrotic syndrome

Question 20

Middle-aged male presents with abdominal and back pain. Radiologic imaging shows impingement of ureters, and involvement of the aorta. Serology shows high IgF4/IgG cell ratio. Diagnosis?

Answer 20

Retroperitoneal Fibrosis (slide 25)

Question 21

Most common primary tumor of the peritoneum

Answer 21

Mesothelioma (better call brown & croupen)

Question 22

Most common metastatic tumor of the peritoneum

Answer 22

Peritoneal Carcinomastosis

- Thickening of the omentum on CT