B. Juntermanns, et al. www.hepato-gastroenterology.org DOI 10.5754/hge09723 Volume 58(106), 265-269, 2011 Hepato-Gastroenterology "iliary( )riginal )pen Access Klatskin-Mimicking Lesions: Still a Diagnostical and erapeutical Dilemma? Benjamin Juntermanns 1 , Gernot Maximilian Kaiser 1 , Henning Reis 2 , Fuat Hakan Saner 1 , Sonia Radunz 1 , Spiridon Vernadakis 1 , Matthias Heuer 1 , Hilmar Kuehl 3 , Andreas Paul 1 and Juergen Treckmann 1 1 Department of General, Visceral and Transplantation Surgery, University Hospital of Essen, Germany 2 Institute of Pathology and Neuropathology, University Hospital of Essen, Germany 3 Department of Diagnostic and Interventional Radiology, University Hospital of Essen, Germany Corresponding Author: Gernot M. Kaiser, MD, Department of General, Visceral and Transplantation Sur- gery, University Hospital of Essen, Hufelandstr. 55, 45122 Essen, Germany; Tel.: +49-201-72384028; Fax:+49- 201-7231137; E-mail: gernot.kaiser@uk-essen.de KEY WORDS: Klatskin-mimicking lesion, hilar cholangiocarcinoma, bile duct tumor, Klatskin tumor, CA19-9 ABBREVIATIONS: AFP, alfa-fetoprotein; CA19-9, carbohydrate antigen 19-9; CEA, carcinoembryonic antigen; CT, computed tomography; ERCP, endoscopic retrograde cholangiopancreaticography; mg/dL, mil- ligram per deciliter; MRCP, magnetic resonance cholangiopancreatography; MRI, magnetic resonance imag- ing; PET/CT, positron emission; tomography/computed tomography; PSC, primary sclerosing cholangitis; PTC, percutaneous transluminal cholangiography; ROC, receiver operator characteristic curve; U/mL, units per milliliter; 18 F-FDG, 18 uoro-2-deoxy-D-glucose. ABSTRACT Background/Aims: e preoperative as well as the intraoperative dierentiation between Klatskin-mim- icking lesions and malignant bile duct tumors at hilar bifurcation is still challenging. Our intention was to review the preoperative diagnostics including preoperative CA19-9 and bilirubin serum levels to compare benign and malignant tumors. Methodology: We analyzed our prospectively established bile duct tumor database. From 1999 to 2008, 238 patients suspicious for hilar cholangiocarcinoma underwent surgery. In 24 patients the postoperative histological diagnosis showed a Klatskin-mimicking lesion. e histological report from 20 out of the 24 patients showed a chronic inammatory transformation of the bile ducts. e histology of two patients showed a primary sclerosing cholangitis and the histological examination of the two remain- ing patients diagnosed a sarcoidosis of the extrahepatic bile duct. Results: Reassessment of preoperative diagnostics did not deliver any change of interpretation of the tumors’ dignity compared to how it had been assessed preoperatively. Also, preoperative CA19-9 serum levels do not show a statistically reliable dieren- tiation between benign or malignant dignity. Conclusion: Current diagnostics cannot dierentiate malignant from benign tumor masses in the hepatic hilum with the necessitated reliability. erefore surgical resection of suspect hilar tumors is still the only appropriate therapy.