Mimics of Cholangiocarcinoma: Spectrum of Disease

Abstract

Cholangiocarcinoma is the second most common primary malignant hepatobiliary neoplasm, accounting for approximately 15% of liver cancers. Diagnosis of cholangiocarcinoma is challenging and the prognosis is uniformly poor, with recurrence rates of 60%-90% after surgical resection. A wide spectrum of neoplastic and nonneoplastic conditions of the biliary tract may masquerade as cholangiocarcinoma, adding to the complexity of management in patients suspected to have cholangiocarcinoma. Mimics of cholangiocarcinoma constitute a heterogeneous group of entities that includes primary sclerosing cholangitis, recurrent pyogenic cholangitis, acquired immunodeficiency syndrome cholangiopathy, autoimmune pancreatitis, inflammatory pseudotumor, Mirizzi syndrome, xanthogranulomatous cholangitis, sarcoidosis, chemotherapy-induced sclerosis, hepatocellular carcinoma, metastases, melanoma, lymphoma, leukemia, and carcinoid tumors. These entities demonstrate characteristic histomorphology and variable clinicobiologic behaviors. The imaging findings of these disparate entities are protean and may be indistinguishable from those of cholangiocarcinoma. In most cases, a definitive diagnosis can be established only with histopathologic examination of a biopsy specimen. © RSNA, 2008 • After reading this article and taking the test, the reader will be able to: List the wide ■ spectrum of biliary tumors and pseudotumors that mimic cholangiocarcinoma. Describe the ■ cross-sectional imaging findings of neoplastic and nonneoplastic conditions of the biliary tract. Discuss how the ■ imaging features of radiologic mimics of cholangiocarcinoma correlate with the pathologic findings. Abbreviations: AIDS = acquired immunodeficiency syndrome, AIP = autoimmune pancreatitis, CCA = cholangiocarcinoma, ERCP = endoscopic retrograde cholangiopancreatography, H-E = hematoxylin-eosin, IPT = inflammatory pseudotumor, PSC = primary sclerosing cholangitis, RPC = recurrent pyogenic cholangitis, 3D = three-dimensional, XGC = xanthogranulomatous cholecystitis RadioGraphics 2008; 28:1115-1129 • Published online 10.1148/rg.284075148 • Content Codes:

Autoimmune Cholangiopathy followed with the Diagnosis of Cholangiocarcinoma

“…The imaging findings of these disparate entities may be indistinguishable from those of cholangiocarcinoma. In most cases, a definitive diagnosis can be established only with histopathologic examination of a biopsy specimen 1 Autoimmune cholangiopathy is a recently proposed entity that describes a specific group of patients presenting overlapping features of primary biliary cirrhosis and autoimmune hepatitis, i.e. clinical and/or biochemical cholestasis, high titer antinuclear antibody, negative antimitochondrial antibody and elevated immunoglobulin G. Liver histology shows primary biliary cirrhosis coexisting with varying degrees of parenchymal inflammation.…”

“…Mimics of cholangiocarcinoma constitute a heterogeneous group of entities that includes primary sclerosing cholangitis, recurrent pyogenic cholangitis, acquired immunodeficiency syndrome cholangiopathy, autoimmune pancreatitis, inflammatory pseudotumor, Mirizzi syndrome, xanthogranulomatous cholangitis, sarcoidosis, chemotherapy-induced sclerosis, hepatocellular carcinoma, metastases, melanoma, lymphoma, leukemia and carcinoid tumors. 1 We report a case of autoimmune cholangiopathy (IgG4 associated sclerosing cholangitis) that had presented with mass-like lesions at liver parenchyma and occlusion of the common bile duct and performed a metal stent inserted in the common bile duct for diagnosis of cholangiocarcinoma in another medical center 5 years ago.…”

CT Evaluation of Disease Pattern in Hilar Cholangiocarcinoma

“…Recurrent pyogenic cholangitis is characterized by repeated attacks of acute pyogenic cholangitis on the background of biliary obstruction by pigmented calculi or biliary strictures. Segmental distribution in RPC has predilection for lateral segment of left lobe, posterior segment of right lobe and the extrahepatic bile ducts [29]. Inflammatory pseudotumor is rare condition that often resembles aggressive malignancy.…”

“…Imaging features of this benign entity are nonspecific and indistinguishable from those of mass-forming type of cholangiocarcinoma. A repeated negative frozen section margin is the helpful indicator of benign disease [29,30]. Intrabiliary metastasis is very rare.…”

“…Common tumors that metastasize to bile ducts are cancers of lung, breast, gall bladder, colon, testis, prostate, pancreas and melanomas. Lymphoma of the bile duct is rare and is usually secondary to systemic disease [29,31].…”