Cystic lesions in the liver : Benign or malignant ?

A 65-year old patient is presented with an ultrasound showing multiple cysts in liver and both kidneys. Computed tomography scan (CT-scan) showed a cyst in the right liver lobe with a largest diameter of 12 cm, suspicious for cystadenocarcinoma. Further staging showed no extrahepatic metastasis. Considering possible malignancy, aspiration of the cyst was not an option because of the risk for ent-metastasis. Resection of the tumour was considered as the best treatment. Peroperatively the cyst was localized with ultrasound, after which an extended right hepatectomy was performed. No peroperative complications occurred. Histological diagnosis was a cyst, originating in dilated von Meyenburg complexes. No signs of a biliary cystadenoma or malignant deformation were observed. A CT-scan 1 year postoperatively showed some other small cysts in the left liver lobe, the patient was free of any complaints. The differential diagnosis in cases of asymptomatic liver cysts will be discussed.