Peribiliary cysts associated with severe liver disease: imaging-pathologic correlation.

OBJECTIVE

Prior pathology reports describe peribiliary cysts in patients who have severe liver disease. The purpose of this study was to determine whether these cysts could be identified on imaging studies, and to determine the range of imaging findings when identified.

SUBJECTS AND METHODS

Imaging and pathologic findings were correlated in 12 patients in whom peribiliary cysts were found on gross inspection of the liver after autopsy (one) or liver transplantation. All patients had been examined with CT and sonography, three patients had undergone MR imaging, and one had had cholangiography. The liver was sectioned in the axial plane at 1-cm intervals, and the porta hepatis and the proximal extrahepatic bile ducts were examined macroscopically. Pathologic findings were recorded and compared with the patients' imaging findings and clinical course.

RESULTS

CT showed the peribiliary cysts in the porta hepatis in 10 of 12 patients. These appeared as discrete cysts in four patients, a tubular structure paralleling the portal structures in four patients, and a string of cysts that simulated abnormal bile ducts in two patients. Sonography showed the cysts in four of 12 patients, as anechoic cystic structures in three and as a septated, tubular channel in one. MR showed the cysts in two of three patients, and T2-weighted images were better than T1-weighted images. The cysts appeared in a cluster in one patient, and as a tubular structure of high intensity on T2-weighted images that simulated a dilated bile duct in the other. Patients were asymptomatic in 11 of 12 cases. In one case, large cysts caused biliary obstruction, which was apparent on CT scans, sonograms, and cholangiograms.

CONCLUSION

Peribiliary cysts associated with a variety of disorders can be detected with CT, sonography, and MR imaging. Recognition of the imaging appearance of these cysts may avoid the misdiagnosis of dilated bile ducts, cystic neoplasm, or abscess. Conversely, when seen on images, these cysts might suggest one of the underlying associated disorders.