PMC4531685_01
Intravenous bolus computed tomography of the abdomen showed a huge cystic mass with thick wall, occupying the most of the right lobe of the liver. The tumor wall has serpentine vascular enhancement during early contrast phase.
kjim-17-4-278-14f1.jpg
PMC4531685_01_kjim-17-4-278-14f1.jpg
f1-kjim-17-4-278-14
Contrast enhanced abdominal computed tomographic (CT) scan showed a thick-walled cystic mass of 15 cm in diameter in the right hepatic lobe with serpentine enhancement in the wall during the early arterial contrast phase (Figure 1).
(A) Celiac angiography revealed a huge hypervascular mass in the right lobe of the liver. Tumor neovascularization was noted at the area of segments 4, 5, 6, 7 and 8. (B) Portovenography revealed total right portal vein defect.
kjim-17-4-278-14f2.jpg
PMC4531685_01_kjim-17-4-278-14f2.jpg
f2-kjim-17-4-278-14
Angiography showed a hypervascular tumor which displaced hepatic artery branches in segments 5, 6, 7 and 8, and neovascularization was noted at the area of segments 4, 5, 6, 7, and 8 (Figure 2).
Gross examination of the excised tumor: Relatively well-demarcated, grayish-white mass measuring 7.5x16.0x4.5 cm in size showed expanding growth pattern. The tumor contained central cystic degeneration and homogeneous and homogenous solid portion.
kjim-17-4-278-14f3.jpg
PMC4531685_01_kjim-17-4-278-14f3.jpg
f3-kjim-17-4-278-14
Several daughter nodules were noted (Figure 3).
Light microscopic examination : (A) Sections of the liver mass showed interlacing fascicles of spindle-shaped nuclei and perinuclear vacuoles (H&E, x200) (B) Tumor showed interlacing spindle-shaped cells arranged in fascicles, with hepatocyte present in the left side. (H&E, x200) (C) Tumor cells showed round nuclei with perinuclear vacuoles. The stroma revealed myxoid change. (H&E, x200)
kjim-17-4-278-14f4.jpg
PMC4531685_01_kjim-17-4-278-14f4.jpg
f4-kjim-17-4-278-14
Most areas consisted of tumor cells which had typical cigar-shaped nuclei with a prominent nucleolus and fibrillary cytoplasm arranged in interlacing bundles and short fascicles (Figure 4). Occasionally, individual and/or aggregated primitive round tumor cells with vacuolated cytoplasm were scattered in the loose chondroid matrix (Figure 4).
Immunohistochemical stains of the resected mass showed positive staining for smooth muscle actin. (Immunohistochemical stain, x200)
kjim-17-4-278-14f5.jpg
PMC4531685_01_kjim-17-4-278-14f5.jpg
f5-kjim-17-4-278-14
The tumor cells had spindle-shaped, hyperchromatic, occasionally pleomorphic nuclei with frequent mitotic figures (5-9/HPF). Immunohistochemical stains for vimentin, desmin, lysozyme and alpha1-antitrypsin were all positive, and keratin, actin and factor VIII were all negative (Figure 5).
Electromicroscopic examination showed myofilaments (arrow) with dense bodies. (EM, x6000)
kjim-17-4-278-14f6.jpg
PMC4531685_01_kjim-17-4-278-14f6.jpg
f6-kjim-17-4-278-14
The tumor cells had spindle-shaped, hyperchromatic, occasionally pleomorphic nuclei with frequent mitotic figures (5-9/HPF). These findings confirmed the myofilamentous nature of the tumor (Figure 6).