Endoscopic retrograde cholangiopancreatography findings of a gallbladder filling defect caused by sludge.

Ultrasound of the abdomen has described intraluminal gallbladder masses or stones without acoustic shadowing which have been termed "sludge balls." This finding has not been previously reported via its x-ray appearance at endoscopic retrograde cholangiopancreatography. This case reports this finding at endoscopic retrograde cholangiopancreatography and emphasizes that it is in the spectrum between suprasaturated bile and choledocholithiasis.