Diagnosis of fibrolamellar cancer
A fibrolamellar carcinoma (FL-Ca) is a primary malignant tumor of the liver of unknown etiology, without cirrhosis and usually without an increase in tumor markers; it occurs mainly in young patients. As it can simulate malignant and benign tumors, particularly focal nodular hypoplasia (FNH), the diagnosis is difficult. Ultrasound and angiography show mostly uncharacteristic features, so ultrasound only has to ascertain that the tumor is there. Angiography can reveal vascular infiltrations and assess the resectability of the tumor, but diagnosis of FL-Ca is not always possible with angiography. CT has the highest specificity if calcifications are present, because calcifications in a tumor similar to FNH are pathognomonic for FL-Ca. By means of hepatobiliary functional scintigraphy FNH can be excluded. MRI seems to be important in differentiating the tumor from FNH, because the central scars of FL-Ca and FNH--if present--have a different signal intensity in T2-weighted images. The histological diagnosis of FL-Ca is also difficult. In patients with resectable tumors or prior to liver transplantation, an operative biopsy should be obtained to verify the diagnosis. In non-resectable tumors sonographic guided biopsy is justified.