Case Report

Mixed Epithelial and Stromal Tumor of the Kidney with Extension into Inferior Vena Cava: Case Report and Discussion of Adult Biphasic Cystic Renal Lesions and the Significance of Vascular Involvement

Figure 4

The spindle cell stroma diffusely positive for smooth muscle actin. Immunoperoxidase stain for smooth muscle actin; original magnification: 125x.