Phrygian cap simulating mass lesion in hepatobiliary scintigraphy.

Hepatobiliary imaging has been used to demonstrate that defects in the region of the gallbladder fossa in sulfur colloid studies correspond to normal gallbladder and not tumor. We report a case of delayed filling of a portion of the gallbladder due to a Phrygian cap anomaly. The case demonstrates that without delayed images incomplete filling of the gallbladder can be confused with a mass lesion in the liver.