Hepatic cysts are common and include sporadic simple cysts, acquired hepatic or peribiliary cysts associated with a number of pathological conditions, and cysts found in hereditary diseases such as autosomal dominant polycystic kidney and liver disease, tuberous sclerosis complex, von Hippel-Lindau disease, and orofaciodigital syndrome type 1 [1]. Simple hepatic cysts occur in 2.5-4.6% of patients referred for ultrasound examination of the abdomen, are more common in women than in men, and their frequency increases with age from 0% in the first two decades to 7% in the eighth decade of life [2, 3]. Simple hepatic cysts are solitary in two-thirds of the patients and no more than three cysts are usually found in those with multiple lesions.

Polycystic liver disease (PLD) has been used to describe the presence of multiple cysts scattered throughout the liver parenchyma, usually found in association with PKD1 and non-PKDl. Rarely, members of families with ADPKD may have PLD without renal cysts. Autosomal dominant PLD without renal cysts has been documented in a small number of families. Isolated PLD without a family history of either ADPKD or PLD cannot be clearly separated from multiple simple cysts. Whether patients with sporadic PLD reflect inadequate ascertainment of the families or new mutations and whether these patients and those with isolated autosomal dominant PLD are genetically different from those with ADPKD and PLD is not known [4]. PLD belongs to the family of hepatobiliary fibropolycystic diseases which are characterized by an overgrowth of biliary epithelium and supportive connective tissue. They include dilatation of the extrahepatic and/or intrahepatic bile ducts, segmental dilatation of intrahepatic bile ducts (Caroli's disease), congenital hepatic fibrosis, autosomal recessive polycystic kidney disease, and PLD. Their