Low power: Pap stain
Loosely cohesive clusters of epithelioid to spindled cells with enlarged irregular nuclei and delicate cytoplasm
Medium power: Pap stain
Epithelial and spindled cells with enlarged irregular and pleomorphic nuclei, prominent nucleoli and delicate cytoplasm
High power: Pap stain
Epithelial and spindled cells with enlarged irregular and pleomorphic nuclei, prominent nucleoli and delicate cytoplasm
Features
• Biphasic population
– High grade epithelial cells
– Spindle to pleomorphic cells
• Delicate cytoplasm
• Enlarged irregular to pleomorphic nuclei
• Prominent nucleoli
• Mitoses
• Necrosis
• Not a specific entity
• Dedifferentiation of renal cell carcinoma
• positive for Vimentin, cytokeratin, may express SMA, CD34
Auger M et al. Diagn Cytopathol. 1993;9(1):46-51.