Hepatobiliary cysts in patients with autosomal dominant polycystic kidney disease: prevalence and CT findings.

OBJECTIVE: Hepatobiliary (intrahepatic and peribiliary) cysts have been described for patients with autosomal dominant polycystic disease. The purpose of this study was to determine the prevalence of these cysts and to describe the wide variation in their appearance on CT scans.

MATERIALS AND METHODS: We studied CT scans for 64 patients (31 men and 33 women) who either had known autosomal dominant polycystic kidney disease or had renal cysts and a family member with polycystic kidney disease. Contrast enhancement was used for 31 patients. CT scans were retrospectively evaluated by consensus by two experienced radiologists. The presence, number, and size of hepatobiliary cysts and the presence and appearance of the two variations, peribiliary and intrahepatic cysts, were analyzed. Peribiliary cysts were determined to be present when many small (< or = 10-mm) cysts were seen adjacent to the larger (up to the third order) portal triad. Cysts present in the hepatic parenchyma but not in contact with the larger portal triad were regarded as intrahepatic cysts.

RESULTS: CT showed hepatobiliary cysts in 56 of the 64 patients (24 men and 32 women; 88%). Intrahepatic cysts were noted in all 56 patients; peribiliary cysts were definitely seen on CT scans for 22 patients and were probably seen (fewer than five cysts and/or cysts located only on one side of the portal vein) on CT scans for 19 patients (73% of all patients with hepatobiliary cysts). Peribiliary cysts appeared as discrete cysts in 31 patients, as a string of cysts in six patients, and as a tubular structure in four patients. Intrahepatic cysts generally were round but occasionally were polygonal. They were variable in number, size, and location.

CONCLUSION: Hepatobiliary cysts were noted in 56 of 64 patients (intrahepatic cysts in all cases and peribiliary cysts in 73% of positive cases). Intrahepatic cysts varied widely in number, size, and location, whereas peribiliary cysts were small and appeared as discrete cysts, a string of cysts, or a tubular structure adjacent to the larger portal triad. It is important to be aware of the wide variety of findings for hepatobiliary cysts so that they are not confused with other abnormalities.