Fig. 2

Immunohistochemical reactivity for synaptophysin, chromogranin A, and Ki-67 in hindgut neuroendocrine tumors. Representative photomicrographs of immunohistochemical staining. a Tumor cells showed strong positive reactivity for synaptophysin (original magnification, ×100; scale bar represents 300 μm). b Tumor cells showed sporadic positive reactivity for chromogranin A (original magnification, ×100; scale bar represents 300 μm). c A few tumor cells showed positive reactivity for Ki-67 (original magnification, ×100; scale bar represents 300 μm)