Figure 1

Renal oncocytoma: the tumor consists of solid, compact nests, acini, tubules or microcysts within a hypocellular hyalinized stroma. (a). In the box: At high-power magnification the predominant cell type, the so-called oncocyte, is round to polygonal with granular eosinophilic cytoplasm, round regular nuclei with evenly dispersed chromatin and a centrally placed nucleolus (b) (Hematoxylin eosin stain)