PMC8114952_01
Abdominal ultrasonography and Sonazoid contrast-enhanced ultrasound images (Sonazoid 0.5 mL bolus injection, Toshiba Aplio 500, and 3.75 MHz convex array probe) of a primary hepatic perivascular epithelioid cell tumor. (a) A heterogeneous hypoechoic nodule is demonstrated on B-mode ultrasound (arrows). (b) Color Doppler flow images reveal abundant blood flow at the tumor margins. (c-f) Sonazoid contrast-enhanced ultrasound in the arterial (c, 23 s), portal (d, 100 s), equilibrium (e, 5 min), and post-vascular (f, 10 min) phases. Hyper-enhancement is observed in the arterial phase, with iso-enhancement in the portal phase and mild hypo-enhancement in the equilibrium and post-vascular phases.
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Abdominal ultrasonography revealed a heterogeneous hypoechoic mass in the right lobe of the liver, with well-circumscribed margins (Figure 1a). Color Doppler flow images showed blood flow at the margin of the mass (Figure 1b). Sonazoid CEUS (Figure 1c-f) revealed homogeneous hyper-enhancement in the arterial phase, iso-enhancement in the portal phase, and mild hypo-enhancement in the equilibrium phase.
Contrast-enhanced computed tomographic (CT) imaging of a primary hepatic perivascular epithelioid cell tumor in the arterial (a, 25-30 s), portal (b, 60 s), and equilibrium (c, 180 s) phases. A heterogeneous enhancement can be seen during the arterial phase, while the contrast agent was washed out during the portal and equilibrium phases (arrows).
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Transverse abdominal contrast-enhanced computed tomography imaging (Figure 2) demonstrated heterogeneous enhancement during the arterial phase and slightly washout during the portal and equilibrium phases.
Transverse abdominal MRI using different contrasts, including T1-weighted of a primary hepatic perivascular epithelioid cell tumor (a), T2-weighted (b), and dynamic contrast-enhanced magnetic resonance imaging (c and d). The tumor showed low signal intensity on T1-weighted imaging and high signal intensity on T2-weighted imaging (arrows). Hyper-intensity was seen in the arterial phase (25-30 s), while hypo-intensity was seen in the portal phase (60 s).
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Traverse abdominal magnetic resonance imaging (MRI) of the mass showed low signal intensities on T1-weighted (T1w, Figure 3a) imaging and high signal intensities on T2-weighted (T2w, Figure 3b) imaging. Dynamic contrast-enhanced MRI showed tumor hyper-intensities in arterial phase images (Figure 3c) and hypo-intensities in the portal phase (Figure 3d).
Pathologic and histopathologic findings of a primary hepatic perivascular epithelioid cell tumor. (a) The gross appearance of the tumor on cut dissection shows a well-demarcated brown to gray tumor surrounded by liver tissue. (b) A low power photomicrograph of liver and tumor histopathology using H & E staining (H & E staining x40). A sharp demarcation between the tumor margin and normal liver parenchyma (star) is observed. (c) A low power photomicrograph of the liver (star) and tumor tissue with CD68 immunohistochemical (IHC) staining (H & E staining x40); the tumor cells are strongly positive for CD68. (d) and (f) High power photomicrographs of normal liver using H & E and CD68 IHC staining, respectively (H & E staining x40). (f) Kupffer cells are strongly positive for CD68 and scattered throughout the liver tissue section (arrow). (e) A high power photomicrograph of the tumor with H & E staining (H & E staining x100). (g) A high power photomicrograph of the tumor using CD68 IHC (H & E staining x100). CD68 positive cells are densely packed and shaped differently from those of the Kupffer cells in normal liver (arrow).
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Necrosis and nuclear atypia were inconspicuous (Figure 4).