PMC3635691_01
Imaging modalities for the liver tumor in segment 6. a Ultrasonography showed a hypoechoic lesion with unclear margins that measured 30 x 25 mm (arrow). b CT on delayed phase demonstrated peripheral enhancement of the tumor (arrowhead).
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F1
On the other hand, ultrasonography showed that the tumor in segment 6 was a hypoechoic tumor, 3 cm in diameter, with unclear margins (fig. 1a). Computed tomography (CT) revealed a low-density lesion with irregular margins and peripheral ring enhancement on delayed phase (fig. 1b).
Pathological findings of tumor in segment 6. a Macroscopically, the mainly whitish tumor with partial hemorrhage and necrosis included a small nodular lesion, slightly yellowish in color. b, c Histological findings showed proliferation of atypical spindle-shaped cells in the tumor, indicating sarcomatoid HCC (b), and a transition area between sarcomatoid pattern (upper right) and trabecular structure, indicating moderately differentiated HCC (lower left) (c). b, c Hematoxylin and eosin staining, x200.
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F2
Macroscopically, the tumor in segment 6 appeared to be hard and whitish with hemorrhage and necrotic tissue (fig. 2a). Histological examination showed proliferation of spindle-shaped sarcomatoid carcinoma cells with unclear trabecular and pseudoglandular structures (fig. 2b). Moderately differentiated HCC with trabecular structure was observed, and transition from sarcomatoid HCC to typical HCC was present (fig. 2c).
Immunohistological examination of the tumor in segment 6. a Anti-CK7 antibody was positive in the sarcomatoid lesion and negative in moderately differentiated HCC and hepatocytes of the non-tumor area. In the non-tumor area, the bile ducts were positive. b Anti-hepatocyte antibody was negative in the sarcomatoid lesion but positive in HCC and hepatocytes in the non-tumor area. c Anti-vimentin was positive in the sarcomatoid lesion but was negative in moderately differentiated HCC and hepatocytes of the non-tumor area. a Hematoxylin and eosin staining. b, c Immunohistochemical staining, x40. T (S) = Sarcomatoid pattern of tumor; T (MD) = moderately differentiated HCC; N = non-tumor area.
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F3
On immunohistochemical examination (fig. 3), carcinoma cells in sarcomatoid HCC were mostly positive for vimentin (DAKO, Glostrup, Denmark), partially positive for cytokeratin 7 (DAKO) and mostly negative but focally positive for hepatocyte (DAKO), whereas those of moderately differentiated HCC were positive for hepatocytes, but negative for cytokeratin 7 and vimentin.