CT and MRI of primary and metastatic fibrolamellar carcinoma: a case series of 37 patients

Abstract

Objective: Fibrolamellar carcinoma (FLC) is a rare disease, with limited radiographic reported information. We assessed the imaging patterns of primary and metastatic FLC.

Methods: CT and MR examinations of patients with FLC were retrospectively reviewed. Imaging features were assessed for primary and recurrent liver tumours, including dimension, enhancement characteristics, and presence or absence of central scars. Locations of nodal and extranodal metastases were also recorded.

Results: Of 37 patients (18 males and 19 females; average age, 23.5 years) with FLC, 24 had imaging of their primary tumour; 13 had metastases at presentation and 7 developed metastases on follow-up. The remaining 13 patients had follow-up imaging of metastatic disease. Primary FLC had a mean diameter >11 cm, with central scars in ten (46%) patients. Most tumours enhanced heterogeneously (96%) and showed arterial enhancement (81%). On MRI, 62% of FLCs were hypointense on T1 weighted imaging and 54% were hyperintense on T2 weighted imaging. 13 patients (54%) had nodal metastases at presentation, mostly in the upper abdomen (92%) and commonly in the chest (38%). Extrahepatic metastases were most frequently pulmonary or peritoneal. Predominantly small and homogeneous intrahepatic recurrences were detected on follow-up in 15 patients.

Conclusion: FLC often presents as a large hepatic tumour with nodal and distant metastases. Thoracic adenopathy and lung metastases were frequently found in our series, suggesting the need for pre-operative and follow-up chest imaging.

Advances in knowledge: Thoracic nodal and lung metastases are common in FLC; therefore, dedicated chest imaging should be part of the evaluation of a patient with FLC.

Figure 1.

Patient selection. Four patients were excluded for mixed tumour histology (one patient), uninterpretable imaging (two patients) or no evidence of disease recurrence on follow-up and no imaging of their primary tumour was available (one patient). Of the 37 patients with imaging, 13 patients only had imaging of metastatic disease on follow-up, with no imaging available for their primary tumour. FLC, fibrolamellar carcinoma; PACS, picture archiving computer systems.

Figure 2.

A 15-year-old female with primary fibrolamellar carcinoma (FLC). (a–c) Intravenous contrast-enhanced CT axial images through the liver (a, b) and chest (c), demonstrate a large right hepatic FLC with typical imaging features, including heterogeneous hypervascularity during the arterial phase (a) and a central scar with calcifications. FLC remains heterogeneous on the portal venous phase, with attenuation similar to liver parenchyma (b). In the chest, mediastinal and hilar adenopathy as well as lung metastases are evident (c). (d–f) Axial MR images through the liver, before (d, e) and after intravenous contrast administration (f), demonstrate a right hepatic FLC with heterogeneous signal predominantly similar to liver parenchyma on T₁ weighted (d) and T₂ weighted (e) sequences. The central scar is heterogeneously hypointense on T₁ and T₂ weighted images, with lack of enhancement on contrast-enhanced images (f).

Figure 3.

A 28-year-old male with primary fibrolamellar carcinoma. Axial MR images through the liver obtained before (a–c) and after intravenous contrast administration (d–f). Pre-contrast images demonstrate a large right posterior hepatic lobe tumour with heterogeneously hypointense signal on T₁ weighted imaging (a) and hyperintense signal on T₂ weighted imaging (b). This lesion remained hyperintense on axial fat-suppressed diffusion-weighted images with b = 800 s mm⁻² (c). On post-contrast T₁ weighted imaging, this lesion was heterogeneously hypervascular during the arterial phase (d), with heterogeneous washout on portal venous phase (e). A satellite lesion was homogeneously hypervascular in Segment 7 more superiorly (f).

Figure 4.

A 16-year-old female with primary fibrolamellar carcinoma. (a–c) Axial MR images through the liver demonstrate a left lateral segment tumour with heterogeneous enhancement on arterial phase (a) and portal venous phase (b). This lesion was uniformly hypointense on delayed hepatobiliary phase, 20 min after injection of gadoxetate disodium (Eovist®/Primovist™; Bayer HealthCare, Leverkusen, Germany) (c).

Figure 5.

A 40-year-old female with fibrolamellar carcinoma intrahepatic recurrence. (a–c) Axial MR images through the liver before (a) or after intravenous contrast administration during the arterial phase (b) or portal venous phase (c) demonstrate a low attenuation mass near the hepatic resection margin. This mass demonstrates homogeneous arterial enhancement (b) and is nearly isodense to surrounding liver on portal venous phase (c).

Figure 6.

A 20-year-old female with fibrolamellar carcinoma (FLC) nodal metastases. (a–c) Intravenous contrast-enhanced axial CT images through the liver (a, b) and chest (c), demonstrate a right hepatic FLC containing a central scar, with enlarged, heterogeneous nodal metastases to the porta hepatis (white arrow) and smaller homogeneous para-aortic nodes (black arrow) (a). Additional supradiaphragmatic adenopathy (arrow) (b) and mediastinal adenopathy (arrow) (c) were present.

Figure 7.

A 23-year-old male with fibrolamellar carcinoma distant metastases. (a–c) Intravenous contrast-enhanced axial CT images through the chest (a, b) and pelvis (c), demonstrate pulmonary metastases (a), a small right posterior pleural metastasis with associated pleural effusion, and extensive pelvic peritoneal metastases with ascites (c).