Contrast enhanced ultrasound examination of biliary cystadenoma: A report of two cases

Biliary cystadenoma is a rare tumor, often encountered as an incidental finding during imaging for other indications. As the lesion is considered pre-malignant, surgical management is advocated, hence a pre-operative differential diagnosis is important. Diagnosis by biopsy or fine needle aspiration (FNA) is sometimes inaccurate and carries a risk of cyst rupture and of seeding, hence imaging is a major contributor to the management decision. Traditionally, ultrasound and CT are considered the two most popular modalities in contributing to a diagnosis, with little emphasis placed on contrast-enhanced ultrasound (CEUS). Two cases are presented where CEUS clearly demonstrated vascularity within the septations of biliary cystadenomas, which could be seen in the arterial as well as porto-venous phases.