Fig. 3

Pathological analyses of the TURBT specimen. A Examination revealed proliferation of spindle tumor cells in the stroma with enhanced mitotic activity (hematoxylin and eosin stain, × 400). Immunohistochemically, the tumor cells were positive for B smooth muscle actin (× 200), C caldesmon (× 200), and D HHF-35 (× 200). E The loss of RB1 expression in the tumor cells was immunohistochemically confirmed (× 200). RB, retinoblastoma; TURBT, transurethral resection of the bladder tumor