PMC6170215_01
EOB-MRI showed a hepatic mass with early-phase hyperattenuation and portal-phase hypoattenuation with gradually wash out the medium (Fig. 1A and B). This was followed by a decreasing the tumour signal in the delayed phase. The hepatobiliary phase showed a wash-out pattern and low signal, which was hypoattenuation, measuring 6.2 cm x 6.0 cm (Fig. 1C and D). The opposed phase of EOB-MRI revealed high intensity of whole the tumour with small low intensity inside the tumour.
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Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid enhanced magnetic resonance imaging (EOB-MRI) showed a hepatic mass with early-phase hyperattenuation and portal-phase hypoattenuation with gradual wash-out in the lateral segment (Fig. 1A and B). The hepatocyte phase showed a typical wash-out pattern and low signal, indicating a hypo-enhanced lesion, measuring 6.2 cm x 6.0 cm (Fig. 1C and D). In addition, out-of-phase EOB-MRI revealed high intensity in the whole tumour (Fig. 1E), with several remarkable small areas of low intensity (Fig. 1F).
On angiography, the tumour was shown as a circumscribed hypervascular mass (Fig. 2A) and central vessels were detected, which illustrated drainage vein from tumour to IVC (Fig. 2B).
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Subsequent angiography revealed the tumour as a well circumscribed hypervascular mass (Fig. 2A) with central vessels, and notably a drainage vein from the tumour to the inferior vena cava (IVC) (Fig. 2B).
The tumour measured 6.3 cm x 6.0 cm in diameter, distinct boundaries, no capsule, light brown tone, solid mild accompanying bleeding inside. Histologically, the tumor was mainly composed of smooth muscle cells and contained small amounts of adipose cells and blood vessels.
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The light brown tumour measured 6.2 cm x 6.0 cm and had no capsule but distinct boundaries, with mild internal hemorrhage (Fig. 3).
On hematoxylin-Eosin staining, the tumour was mainly composed of smooth muscle cells and contained small amounts of adipose cells and blood vessels.
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Histologically, hematoxylin and eosin staining showed that the tumour was composed mainly of smooth muscle cells, with only small numbers of adipose cells and blood vessels (Fig. 4).
On immunohistochemical staining, the tumour was negative for hepatocyte structure, but positive for human melanin black 45(HMB-45) and the smooth muscle cells were positive for a melanocytic cell-specific monoclonal antibody (Melan-A).
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Immunohistochemical staining revealed that the tumour had no evident hepatocyte structure, but was strongly positive for HMB-45, which is the most sensitive marker of AML, and the smooth muscle cells were positive for Melan-A (Fig. 5).