The case was further reviewed in an MDM, with the favored diagnosis of cholangiocarcinoma. Further staging has not shown metastatic disease. Surgical resection was offered: 

Macroscopy: Labeled "Left lobe liver".  A segment of the liver with a roughened resection surface 110 x 63 mm (inked black).  Focally, the capsule is retracted over a 120 x 35 mm area (inked green).  There is a small amount of attached fat 50 x 20 mm, within which there is a tubular structure approximately 65 mm long and up to 8mm wide resembling a the cholecystic duct.  This structure corresponds to the amputated staple margin there appears to terminate at the hilum. Mottled irregular grey patches are present over the surface of the capsule overlying the tumor. There is a 30 mm staple line on the resection margin (removed, resulting in surface inked yellow).  Sectioning reveals an irregularly shaped white, firm tumor 70 x 55 x 54 mm extending through the parenchyma and abutting the resection margin and the stapled duct margin.  The background liver is tan-brown to red. 

Microscopy: Sections were taken through the liver, focally showing expanded bile duct within which there is a proliferation of glandular spaces of varying size lined by moderately pleomorphic epithelium. Adjacent to this, there is the extensive infiltration of the adjacent parenchyma by glands of varying caliber lined by moderately pleomorphic epithelium showing nuclei with a slightly vesicular nucleus and small nucleoli and mitoses. In areas, the tumor has a hyalinised connective tissue associated with the infiltrating cells. There is an evident perineural invasion. The tumor is seen to focally extend to the ductal/hilar are margin. Vascular invasion is not seen. Away from this area, the hepatic parenchyma shows portal tract chronic inflammation and evidence of biliary stasis. Bile ducts away from the lesion, show no periductal sclerosis or inflammation extending into the epithelium.
Tumor cells are immunoreactive with cytokeratin 7 and show some intermixed immunoreactivity with cytokeratin 20. There is no reaction with Hepatocyte specific antigen or CD10.

Conclusion: Left lobe of liver -  intrahepatic cholangiocarcinoma showing perineural invasion, present at the ductal/hilar resection margin. Adjacent liver shows no evidence of cholangitis.