This is a nice example of clear cell renal cell carcinoma that demonstrates several aspects of the tumor:

• classical yellow/golden macroscopic appearance
• propensity to grow into the renal vein, sometimes extending into the inferior vena cava and right ventricle
• cells classically have clear cytoplasm; this is actually a processing artefact secondary to removal of the cytoplasmic lipid during processing
• often has marked variation in tumor cell morphology and grade across the tumor; this is attributed to 'clones' of tumor cells arising from the initial tumor clone