The difficulty of distinguishing retroperitoneal schwannoma from liver tumor in the caudate lobe

: A 68-year-old woman was admitted to our hospital for the evaluation of an abdominal tumor. Both ultrasonography and computerized tomography revealed a mass at the caudate lobe of the liver. However, it was difficult to distinguish the mass from a liver tumor in the caudate lobe. The laboratory data showed only a slight elevation of the serum gamma-GTP level and ICG retention. The abdominal arteriography revealed a vascular tumor located in the retroperitoneal space, which was receiving its blood supply from the right inferior phrenic artery. When a laparotomy was performed, a yellowish solid mass (8 X 6 X 4.5 cm) was found behind the lateral segment of the left liver lobe. Histological examination showed interlacing bands of uniform spindle cells of which elongated nuclei were arranged in a palisading pattern. The tumor was diagnosed as schwannoma. Literatures on retroperitoneal schwannoma are reviewed, as this tumor is relatively rare.