Intraductal oncocytic papillary neoplasm of the liver: case and review of a rare variant.

Intrahepatic cholangiocarcinoma (ICCA) comprises 10% of all cholangiocarcinoma (CCA). It can be divided into three macroscopic subtypes, the least common of which is characterized by intraductal growth and believed to be more amenable to good outcomes with surgical resection compared to other ICCA. Recently, the rare finding of oncocytic differentiation has been described in this subtype and termed <<intraductal oncocytic papillary neoplasm>> (IOPN), but it remains unclear if the presence of oncocytes confers a different tumor behavior. We present the eighth reported case of IOPN, which to our knowledge, is the first such case that, due to its location and vascular compromise, required orthotopic liver transplantation (OLT). This case adds to the little that is known about the behavior of IOPN and supports the observation that resection, or OLT when resection is not possible, is a valid treatment option.