Michael Leigh Wells MD, Presenter: Nothing to Disclose

Sudhakar Kundapur Venkatesh MD, FRCR, Abstract Co-Author: Nothing to Disclose

Geoffrey Bates Johnson MD, PhD, Abstract Co-Author: Nothing to Disclose

Jeff L. Fidler MD, Abstract Co-Author: Nothing to Disclose

David Maitland Hough MD, Abstract Co-Author: Nothing to Disclose

Joel Garland Fletcher MD, Abstract Co-Author: Grant, Siemens AG

Vishal Chandan MBBS, Abstract Co-Author: Nothing to Disclose

Biphenotypic primary hepatic neoplasms characterized by both hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCA) differentiation are rare. We performed a retrospective study to review the imaging and laboratory findings in 47 patients.

In this institutional review board approved study, we retrospectively searched our institutional electronic medical records for patients with pathologically confirmed biphenotypic tumors. Clinical data and serum tumor markers were recorded. Two reader consensus of imaging features obtained for computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) and ultrasound.

Chronic liver disease (CLD) was present in 36% of subjects; cirrhosis in 28%. Serum AFP was elevated in 29/42 (69%), CA 19.9 in 21/35 (60%) and both AFP and CA 19.9 were elevated in 16/34 (47%). On MRI, tumors were T2 hyperintense in 18/19 (95%) and T1 hypointense in 19/19 (100%). Only 1/27 (4%) exhibited classic HCC feature of arterial hyperenhancement followed by washout. On CT and MRI, nearly three quarters (20/27, 74%) had peripheral hyperenhancement followed by peripheral washout or fade coupled with gradual central enhancement. Other patterns included persistent peripheral enhancement on all phases (n =3), separate foci of arterial and delayed enhancement (n=2), and hypoenhancement (n=1). Pseudocapsule was present in 6; biliary obstruction in 3 and liver capsule retraction in 8. Peripheral hypoechogenicity and central hyperechogenicity was the most common ultrasound feature, 5/12 (43%). PET demonstrated hypermetabolism in 9/11 (82%).

Biphenotypic tumors do not show strong association with CLD and serum tumor markers are inconsistently elevated. They exhibit variable imaging characteristics on CT and MRI, but classic features of HCC are usually not seen. Most have enhancement patterns which may suggest alternative diagnoses such as biphenotypic tumor, CCA or metastasis. Two distinct tumor components are rarely seen. Discordance between imaging findings and laboratory tumor markers should raise suspicion of biphenotypic tumor. Mixed tumors tend to be very metabolically active at FDG PET. Ultrasound is not specific.

Suggesting an etiology other than HCC may be an important role of imaging in these patients given the significant differences in management of HCC compared with biphenotypic tumors, CCA or metastases.

Wells, M, Venkatesh, S, Johnson, G, Fidler, J, Hough, D, Fletcher, J, Chandan, V, Biphenotypic Intrahepatic Cholangiocarcinoma and Hepatocellular Carcinoma: Imaging Features on MRI, CT, Ultrasound and PET.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007120.html