Figure 7. Pathological examination of the presacral tumor revealing tumor cells with a 4.5% Ki-67-positive cell ratio, which were positive for synaptophysin and negative for chromogranin A, similar to the NET in the liver. The upper left shows HE, the upper right shows synaptophysin, the lower left shows chromogranin A, and the lower right shows Ki-67. Scale bars, 100 μm (low-power field) and 20 μm (high-power field). NET – neuroendocrine tumor, HE – hematoxylin-eosin staining.