GI Section 1: Large Bowel/Rectum (Misc LB Pathology)

Question 1

Ulcerative colitis, and to a lesser degree Crohns, is the primary cause.

Clostridium difficile

Answer 1

Toxic Megacolon

Question 2

Answer 2

Toxic Megacolon

Gaseous dilation distends the transverse colon (on upright films), and the right and left colon on supine films.

Lack of haustra and pseudopolyps are also seen

Question 3

Why wont you do barium enema in toxic megacolon?

Answer 3

Risk of perfroration

Question 4

Ulcers of the penis and mouth.

Answer 4

Behcets

Question 5

Behcets

Answer 5

Can also affect GI tract (and looks like Crohns) - most commonly affects the ileocecal region

Question 6

a cause of pulmonary artery aneurysms

Answer 6

Behcets

Question 7

Answer 7

Epiploic Appendagitis

Epiploic appendages along the serosal surface of the colon can torse, most commonly on the left

There is not typically concentric bowel wall thickening (unlike diverticulifis).

Question 8

Answer 8

Omental infarction

itypically a larger mass with a more oval shape and central low density.

Common on the right (R O I- right omental infarct). Both entities are self-limiting.

Question 9

Classic pathway of appdendicitis

Answer 9

obstruction (fecalith or reactive lymphoid tissue) -> mucinous fluid builds up increasing pressure -> venous supply is compressed -> necrosis starts ->
wall breaks down -> bacteria get into wall -> inflammation causes vague pain (umbilicus) -> inflamed appendix gets larger and touches parietal peritoneum (pain shifts to RLQ).

Question 10

most common mucinous tumor of the appendix.

Answer 10

Mucinous cystadcnomas

Question 11

They look similar to cystadenocarcinomas and can perforate leading to pseudomyxoma peritonei

Answer 11

Appendix Mucocele

Question 12

Answer 12

Appendix Mucocele

“Onion sign” - layering within a cystic mass

Question 13

Colonic Volvulus different flavors:

Answer 13

Sigmoid
Cecal
Cecal Bascule

Question 14

Most common adult form of colonic volvulus

Answer 14

Sigmoid

Question 15

Answer 15

Sigmoid Volvulus

Coffee Bean sign (inverted 3 sign)

Question 16

Answer 16

SIgmoid Volvulus

Frimann Dahl’s Sign

which refers to 3 dense lines (arrows) converging towards the site of obstruction (star).

Points to the RUQ. Recurrence rate after decompression = 50

Question 17

Associated with people with a “long mesentery.” More often points to the LUQ. Much less common than sigmoid.

Answer 17

Cecal Volvulus

Question 18

Anterior folding of the cecum WITHOUT twisting

Answer 18

Cecal Bascule

Question 19

Answer 19

dilation o f the cecum in an ectopic position in the middle abdomen, without a mesenteric twist

terminal ileum is not involved

Question 21

Younger Person - with prior surgery, a mass, or a 3rd Trimester Baby destined to wear the jeweled crown of Aquilonia upon a troubled brow
Extends Towards LUQ
Haustra is maintained
Small Bowel is dilated

Answer 21

Question 21

Old Grandma - who needs to poop Extends Towards RUQ
Haustra is Lost
Ascending and Transverse
Colon might be Dilated

Answer 21

Question 22

marked diffuse dilation of the large bowel, without a discrete transition point.

Answer 22

Colonic Pseudo-Obstruction

aka Colonic Ileus, Ogilvie Syndrome

Question 23

Bacterial overgrowth in a blind loop which gets no poop (surgery that creates a blind loop without poop). Classic with pre-existing Inflammatory Bowl Disease.

Answer 23

Diversion Colitis /Pouchitis

Question 24

2 types of Colitis Cystica

Answer 24

1. Superficial
2. Deep/Profunda

Question 25

The superficial kind consists of cysts that are small in the entire colon. It’s associated with vitamin deficiencies and tropical sprue. Can also be seen in terminal leukemia, uremia, thyroid toxicosis, and mercury poisoning.

Answer 25

Superficial Colitis Cystica

Question 26

These cysts may be large and are seen in the pelvic colon and rectum.

Answer 26

Deep/proifunda Colitis cystica

Question 27

Phleboliths in the rectum

associated with

Klippel-Trenaunay-Weber and Blue Rubber Bleb.

Answer 27

Rectal Cavernous Hemangioma

Question 28

Answer 28

Gossypiboma

Heterogeneous intra-peritoneal collection located behind anterior abdominal wall at the level of the surgical incision site. It shows thin enhancing wall with multiple small internal gas bubbles and hyperdense curvilinear structures.