Assessment of malignant liver tumors in children

Abstract

Imaging plays a crucial role in the management of a child with a suspected liver tumor. There are various important differences between pediatric and adult practice, and in particular several liver tumor types that are almost never seen in adults are not uncommon in children. The radiologist makes important contributions to the diagnosis through non-invasive imaging and often biopsy. This paper describes imaging tips for the radiologist, including a discussion of the PRETEXT system for staging primary malignant tumors.

Figure 1

The PRETEXT system classifies malignant primary liver tumors of childhood according to the potential amount of unaffected liver that would remain after a typical surgical resection. Various other configurations are possible for each stage^[19]. (A) PRETEXT I; (B) PRETEXT II; (C) PRETEXT III; (D) PRETEXT IV.

Figure 2

Venous involvement in the PRETEXT system as shown in three patients with hepatoblastoma. Involvement is defined as obliteration (A,B) or encasement (C) of the vein, or the presence of intravascular tumor (D). (A) The left hepatic vein (long arrow) and two middle hepatic veins (short arrows) are seen, but no vessel is identified in the expected position of the right hepatic vein. (B) A large accessory right hepatic vein (arrow) is identified on a more caudal image. It can be inferred that the right hepatic vein is completely obliterated. (C) The right hepatic vein is completely surrounded by tumor (arrow). (D) There is intravascular tumor in the right atrium (arrow).