Macroscopy: CT-guided FNA of mediastinal mass - 2 passes: 3 air-dried smears, 3 alcohol-fixed smears and cell block prepared. Cytologist in attendance.
Microscopy: Slides show blood and clusters of malignant tumour cells. These cells have large nuclei with prominent nucleoli and a large amount of pale to clear cytoplasm.
A cell block has been prepared of the tumour cells show positive staining for PAX8 and broad-spectrum cytokeratin, but do not stain with CD10. The findings are consistent with metastatic renal cell carcinoma.
Conclusion: Mediastinal mass, CT-guided FNA: Positive for malignancy. Features consistent with metastatic renal cell carcinoma.