Investigations:
Laboratory data at the time of presentation to our institution showed almost no abnormalities, with an alkaline phosphatase concentration of 321 IU/L, gamma-glutamyl transpeptidase concentration of 48 IU/L, alanine aminotransferase concentration of 69 IU/L, and aspartate aminotransferase concentration of 35 IU/L. The bilirubin concentration was 0.7 IU/L, and she was negative for hepatitis serology. Ultrasound revealed a well-defined septated cystic mass in the left liver lobe with a maximum diameter of 45 mm (Fig. 1a–c). Subsequent abdominal computed tomography (CT), contrast-enhanced CT, and drip infusion cholecystocholangiography CT showed no contrast effect of the cyst, no calcification or enhanced nodules, and no bile duct traffic (Fig. 1d–f). Magnetic resonance imaging of the liver with cholangiopancreatography confirmed the presence of a multifocal cyst in liver section III (Fig. 1 g, h). There was no traffic between the cyst and the bile duct. Bile cytology was negative.
Differential diagnosis:
A simple cyst was thought to be unlikely, and a provisional diagnosis of a complex cyst, mucinous cystic neoplasm, or hepatic peribiliary cysts was made. Given the patient’s age and symptomology, the growing size of the cyst, biliary compression, and risk of malignant transformation, we decided to perform surgical resection rather than to continue observation.