Imaging of mixed epithelial and stromal tumor of the kidney: A case report and review of the literature

Figure 1 Computed tomography. A: Non-enhanced computed tomography image showing a round, well-defined, and mixed mass; B: Enhanced computed tomography image during the corticomedullary phase; C: Nephrographic phase; D: Delayed enhancement of the solid part and no enhancement of the cystic part.

Figure 2 Moderate or mild enhancement in the solid component after contrast enhancement. A: Coronal T2-weighted image showing an exophytic cystic-solid mass in the lower pole of the left kidney; B: Cystic region shows T1 hypointensity and T2 hyperintensity; C: Solid region shows T1 hypointensity and T2 hyperintensity; D: Contrast-enhanced magnetic resonance imaging during the corticomedullary phase; E: Nephrographic phase; F: Excretory phase showing that the tumor’s cystic parts were not enhanced and the tumor’s solid parts were enhanced to a moderate or mild degree that increased with time.

Figure 3 Gross specimen showing a well-defined mass with a white, fish-like texture.

Figure 4 Histopathology. Microscopically, the tumor was composed of fibrous cells arranged in bundles. Fiber growth was observed in the lesion. Small tubular structures were observed within and around the tumor (magnification, ×100).