Fig. 3

Microscopy of conventional staining of pathological specimens. The tumor had slit-like vessels (a, arrows) and expansive compression of the adjacent normal renal tissues (a, arrowheads). The tumor constituted spindle-shaped cells situated in variable directions in dense collagenous stroma (b) and had diffuse CD34 expression throughout the tumor (c). A small number of tumor nuclei were positive for Ki-67, with a Ki-67 labeling index of 0.6–0.7 % (d, arrow). Mitosis, atypia, necrosis and hemorrhage were not found by microscopy in the tumor (a to d). These findings about the kidney tumor are consistent with a classic SFT without malignant nature. Original magnification: x20, x400, x200 and x100 for A, B, C and D, respectively. HE, hematoxylin and eosin