Diagnostic Ultrasound - Abdomen and Pelvis

Gallbladder Cholesterol Polyp
Diagnoses: Biliary System
Gallbladder Carcinoma
• Irregular soft tissue thickening of GB wall or mass
• Early noninvasive carcinoma may be homogeneous with
broad base
• Evidence of invasion to adjacent liver parenchyma and
regional nodal metastases
• Increased chaotic internal vascularity
GB Metastases
• Most common from melanoma and adenocarcinoma of GI
origin
• Hyperechoic, broad-based polypoidal mass
• Usually > 10 mm in size
• Clinical history of known primary malignancy
PATHOLOGY
General Features
• Etiology
○ May be attributed to absorption of cholesterol from
supersaturated bile
○ Does not predispose to cholecystitis or functional
derangement
• Genetics
○ No documented genetic predisposition
• Associated abnormalities
○ Occasionally associated with cholelithiasis
Gross Pathologic & Surgical Features
• Multiple yellow nodules on cut sections
• Sessile/pedunculated smooth mucosal projections
• Intact mucosal surface
• GB wall is not thickened unless complicated or inflamed
Microscopic Features
• Focal accumulation of lipid-laden macrophages underneath
normal columnar epithelium
• Fibrous stroma
• Infiltrated with variable degree of chronic inflammatory
cells
• Intact mucosa with smooth projections
• No evidence of muscularis layers infiltration
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Asymptomatic, incidental finding on US for other
purposes
• Other signs/symptoms
○ Mild nonspecific right upper abdominal discomfort
Demographics
• Age
○ More common in middle age
• Gender
○ M < F
• Epidemiology
○ 5% of population have polyps; 50% are cholesterol
polyps
○ 6% of cholecystectomy specimens
Natural History & Prognosis
• No malignant potential
• No interval increase in size on serial follow-up US
Treatment
• Cholecystectomy only indicated if
○ Symptomatic
○ Associated with gallstones or cholecystitis
○ Risk factors for malignant polyp
– Age > 50 years
– Size > 10 mm (most malignant polyps > 10 mm)
– Serial increase in size on follow-up US
– Sessile morphology
– Gallstones
– Solitary lesion
– Primary sclerosing cholangitis
DIAGNOSTIC CHECKLIST
Consider
• Consider neoplastic GB polyp if size > 10 mm, irregular
outline, sessile morphology with abnormality of GB wall
and invasion of adjacent structures, growth on serial US
examinations
• Further evaluation with CECT or enhanced MR
Image Interpretation Pearls
• Multiple small, round/ovoid masses attached to GB wall
with no posterior acoustic shadowing
• Easily differentiated from nonshadowing cholelithiasis or
biliary sludge by demonstrating immobility of polyp
SELECTED REFERENCES
1. Sebastian S et al: Managing incidental findings on abdominal and pelvic CT
and MRI, Part 4: white paper of the ACR Incidental Findings Committee II on
gallbladder and biliary findings. J Am Coll Radiol. 10(12):953-6, 2013
2. Terada T: Histopathologic features and frequency of gall bladder lesions in
consecutive 540 cholecystectomies. Int J Clin Exp Pathol. 6(1):91-6, 2013
3. Cairns V et al: Risk and Cost-effectiveness of Surveillance Followed by
Cholecystectomy for Gallbladder Polyps. Arch Surg. 147(12):1078-83, 2012
4. Gallahan WC et al: Diagnosis and management of gallbladder polyps.
Gastroenterol Clin North Am. 39(2):359-67, x, 2010
5. Chattopadhyay D et al: Outcome of gall bladder polypoidal lesions detected
by transabdominal ultrasound scanning: a nine year experience. World J
Gastroenterol. 11(14):2171-3, 2005
6. Sandri L et al: Gallbladder cholesterol polyps and cholesterolosis. Minerva
Gastroenterol Dietol. 49(3):217-24, 2003
7. Sugiyama M et al: Endoscopic ultrasonography for differential diagnosis of
polypoid gall bladder lesions: analysis in surgical and follow up series. Gut.
46(2):250-4, 2000
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