Abstract
Cholangiocarcinoma, an adenocarcinoma arising from the epithelium of biliary ducts, is considered the second most common hepatic malignancy after hepatocellular carcinoma with increasing incidence over the past 3 decades. Many imaging modalities with correlation to clinical presentation are used for the diagnosis and staging of cholangiocarcinoma. However, the diagnosis of cholangiocarcinoma is still challenging due to the presence of some benign and malignant conditions that mimic the clinical presentation and radiological findings of this disease. One of those mimics is the condition of intrabiliary hydatid cyst rupture which can cause biliary obstructive symptoms over weeks with radiological findings that may be indistinguishable from those of cholangiocarcinoma and specifically klatskin tumor when found at the bifurcation of the common hepatic duct. In such a confusing situation, the correct preoperative diagnosis and potential treatment of the disease could both be made possible using Endoscopic Retrograde Cholangiopancreatography avoiding unrequired surgical interventions.