Teaching Case

Unspecific abdominal complaints. Slight elevation of AST, ALT and gamma-GT. No previous history of hepatic diseases or risk factors (alcohol, drugs). Normal serum levels of alpha-FP.

Recent complaints of unspecific abdominal discomfort and pain in the right shoulder. Clinical data otherwise irrelevant. No previous history of hepatic diseases namely alcohol or drug abuses. Laboratory findings revealed high levels of AST, ALT and gamma-GT. Serology for viral hepatitis and tumor markers was negative, including alpha-FP levels. Imaging work-up of the patient consisted of an upper abdominal sonography, helical-CT and MRI.

The fibrolamellar variant of hepatocellular carcinoma (FL-HCC) is a very rare hepatic tumor (approximately 1% of all hepatic tumors and less than 10% of all hepatocellular carcinomas), mainly affecting young healthy female patients without underlying liver disease. This tumor carries out a better prognosis than the usual HCC being amenable to surgical treatment or liver transplantation in a high percentage of cases with high rates of resectability. However, absence of relevant symptoms may lead to their large size and/or extra-hepatic disease at initial presentation, as it happened in the present case. Metastatic lymphadenopathy is the most frequent extra-hepatic finding. Alpha-FP levels are typically normal. From the imaging point of view the most important criteria for its diagnosis are the detection of coarse central calcifications (15-25% of cases) and hypervascular features on dynamic study. Of utmost importance is the demonstration of a hypointense central scar on MRI, both on T1- and T2-w images, also showing lack of enhancement. Differential diagnosis should include conditions such as focal nodular hyperplasia. However, this benign tumor exceptionally contains calcifications and generally displays a T2-w hyperintense and vascularized central scar, contrarily to FL-HCC. On pathology the characteristic pattern of collagenous lamellar fibrosis, relatively acellular, is the histological hallmark of FL-HCC.