Gastrointestinal: Gallbladder

Question 1

When should you consider the gallbladder to be dilated?

Answer 1

> 4 cm in short-axis diameter

Note: The gallbladder can be mildly dilated in a normal fasted pt.

Question 2

Cutoff for gallbladder wall thickening?

Answer 2

> 3 mm

Question 3

What are the anatomical sections of the gallbladder?

Answer 3

Question 4

Arrows

Answer 4

Spiral valves of Heister

Question 5

Why does the cystic duct appear tortuous in this MRCP?

Answer 5

Spiral valves of Heister (normal anatomy)

Question 6

Persistent bile leak s/p cholecystectomy…

Answer 6

Think about accessory cystic ducts (ducts of Luschka)

Question 7

Gallbladder finding

Answer 7

Phrygian cap

Question 8

Intrahepatic gallbaldder

Answer 8

Variant anatomy where the gallbladder is within the liver (usually right above the interlobular fissure)

Question 9

CT cholangiogram in a pt with persistent bile leak s/p cholecystectomy…

Answer 9

Think accessory cystic duct (of Luschka)

Note: Extravasated contrast is seen adjacent to the cholecystectomy clips and a small branch of the right hepatic duct is seen (possible accessory duct of Luschka).

Question 10

Gallstones in a child…

Answer 10

Think sickle cells disease

Note: These are usually cholesterol stone (75%) but can also be pigmented stones (25%).

Question 11

Why might a gallstone not have posterior shadowing on ultrasound?

Answer 11

• Its not actually a stone
• Its <3 mm

Question 12

Gallbladder ultrasound

Answer 12

Dirty shadowing from the anterior gallbladder wall, suspicious for emphysematous cholecystitis

Note: Emphysematous cholecystitis is at a high risk of perforation.

Question 13

What is the most specific ultrasound finding of acute cholecystitis?

Answer 13

Positive sonographic Murphys sign AND cholelithiasis

Question 14

Negative sonographic Murphys sign

Answer 14

Gangrenous cholecystitis (necrosis of gallbladder)

Note: Sloughed membranes are highly suspicious. Sonographic Murphys sign is often negative (due to necrosis of the nerves).

Question 15

Emphysematous cholecystitis is most common in what pt population?

Answer 15

Elderly diabetics

Question 16

Gallbladder wall thickening and pericholecystic fluid in a pt s/o heart valve replacement…

Answer 16

Think acalculus cholecystitis

Question 17

Gallbladder not visualized on HIDA scintigraphy of a pt in the ICU…

Answer 17

Think acalculus cholecystitis

Question 18

Mirizzi syndrome

Answer 18

Common hepatic duct obstruction secondary to mass effect from a gallstone in the cystic duct

Note: The impacted stone can eventually erode into the common hepatic duct or GI tract.

Question 19

Risk factors for Mirizzi syndrome

Answer 19

Low cystic duct insertion

Note: This results in a more parallel course and closer proximity to the common hepatic duct.

Question 20

Pts with Mirizzi syndrome are at a 5x risk of…

Answer 20

Gallbladder cancer

Question 21

Bouveret syndrome

Answer 21

Gastric outlet obstruction secondary to a gallstone obstructing the gastric pylorus or proximal duodenum

Note: Bouveret causes belching (from gastric distention). Gallstone ileus is more commonly caused by a gallstone obstructing the ileocecal valve.

Question 22

What is the difference between gallbladder adenomyomatosis and cholesterolosis?

Answer 22

In gallbladder adenomyomatosus, there is cholesterol crystal deposition in an intraluminal location (within Rokitanky-Aschoff sinuses)

In cholesterolosis, there is cholesterol and triglyceride deposition within the gallbladder wall and is associated with the formation of cholesterol polyps

Note: Both are benign and the distinction is clinically irrelevant.

Question 23

Answer 23

Gallbladder adenomyomatosis

Note: This is the comet-tail artifact (highly specific for adenomyomatosis).

Question 24

What are the 3 major forms of gallbladder adenomyomatosis?

Answer 24

• Segmental (annular)
• Fundal (localized)
• Diffuse (generalized)

Note: The localized form can’t be reliably differentiated from gallbladder cancer.

Question 25

Answer 25

Porcelain gallbladder Note: Should have cholecystectomy due to increased risk for gallbladder cancer.

Question 26

Treatment for porcelain gallbladder

Answer 26

Cholecystectomy (due to increased risk for gallbladder cancer)

Question 27

What is the most common type of gallbladder polyp?

Answer 27

Cholesterol (not actually polyps, but enlarged papillary fronds full of cholesterol laden macrophages) Note: Adenomas and papillomas are much less common.

Question 28

Management of incidental gallbladder polyps

Answer 28

- <5 mm (none) - 5-10 mm (annual ultrasound to look for growth) - >10 mm (consider surgical removal)

Question 29

What features of a gallbladder polyp make you more suspicious about malignancy?

Answer 29

- Large size (>5 mm) - Sessile (not pedunculated) - Solitary (multiple are more likely to be cholesterol) - Enhancement greater than adjacent gallbladder wall - Internal flow on color Doppler - Growth

Question 30

Elderly woman with RUQ pain, weight loss, anorexia, and a longstanding history of gallstones...

Answer 30

Think gallbladder cancer Note: Most gallbladder cancers are associated with gallstones (85%).

Question 31

Risk factors for gallbladder cancer

Answer 31

- Gallstones (especially Mirizzi syndrome) - Primary sclerosis cholangitis - Chronic cholecystitis - Porcelain gallbladder - Large gallbladder polyps (>1 cm)

Question 32

Prognosis of gallbladder cancer

Answer 32

Horrible (due to late presentation because it is usually asymptomatic early on) Note: 80% of cases have direct tumor invasion of the liver or portal nodes at the time of diagnosis.