Diagnostic Ultrasound - Abdomen and Pelvis

Gallbladder Cholesterol Polyp
Diagnoses: Biliary System
TERMINOLOGY
• Focal gallbladder (GB) cholesterosis, polypoid cholesterosis
• Abnormal deposit of cholesterol ester producing villous-like
structure covered with single layer of epithelium and
attached via delicate stalk
IMAGING
• Transabdominal US is most sensitive technique for
detecting small cholesterol polyps
• Optimize resolution and set focal zone to level of GB mass
to improve accuracy of mass characterization
• Scan in supine, decubitus (left > right lateral) positions to
demonstrate immobility of GB polyp
• Usually 2-10 mm in size
• Most commonly in middle 1/3 of gallbladder
• Intact GB wall
• Avascular or hypovascular on Doppler examination
• Larger lesions may have slight internal vascularity
• Variant US appearances
KEY FACTS
○ Large size: Lesions up to 20 mm have been described
– Fine pattern of echogenic foci, best seen with
endoscopic ultrasound
○ Pedunculated with well-defined stalk from GB wall
• < 6 mm: No follow-up
• 7-9 mm: Yearly US follow-up to monitor size
• > 10 mm: Surgical consult
DIAGNOSTIC CHECKLIST
• Multiple small, round/ovoid masses attached to GB wall
with no posterior acoustic shadowing
• 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
(Left) Graphic shows wellcircumscribed,
pedunculated
nodules ſt arising from the
gallbladder (GB) wall,
suggestive of cholesterol
polyps. Note the preserved GB
wall without invasion to the
adjacent liver parenchyma.
(Right) Transverse ultrasound
shows a small, lobulated polyp
ſt with diffuse mild wall
thickening st.
(Left) Longitudinal ultrasound
in the left lateral decubitus
position shows a small polyp
ſt with no retraction of the
adjacent wall. (Right)
Longitudinal ultrasound in the
left lateral decubitus position
shows multiple small, smooth
mural polyps ſt.
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