Hilar Inflammatory Pseudotumour with Hepatic Artery Atheroma- mimicker of Klatskin Tumour.

Inflammatory pseudotumour of hilar biliary structures is an extremely rare benign lesion that can mimic hilar cholangiocarcinoma. Clinical presentation and imaging findings often pose diagnostic difficulties. Main histopathological findings are the presence of myofibroblastic spindle cells, plasma cells, macrophages, and lymphocytes without cellular atypia or atypical mitotic figures. We describe a case of 62 year old male who presented with surgical obstructive jaundice. Imaging revealed a mass lesion involving the biliary confluence with upstream dilatation of biliary tree. Diagnosis of hilar cholangiocarcinoma with type III hilar block was made. Intraoperately hilar mass lesion was found which was encasing right hepatic artery with no evidence of metastasis. The patient underwent Right hepatectomy with caudate lobectomy with complete common bile duct (CBD) excision with Roux en Y hepaticojejunostomy. Unexpectedly histopathological examination showed no evidence of malignancy and revealed hilar inflammatory pseudotumour with hepatic artery atherosclerosis. Preoperative imaging, operative management, pathologic diagnosis and literature review are being presented in view of rarity of the case.