Figure 1: (a) The nodular appearance of the lesion is displayed. The arrow shows nodular area. Scale bar = 500 μm. (b) The lesion area presents nodular and lobulated. Scale bar = 200 μm. (c) The cell morphology is relatively single, cohesive polygonal or oval cells. Scale bar = 100 μm. (d) The aggregates of cells show abundant cytoplasm and ovoid or twisted nuclei. Scale bar = 50 μm.