A 55-year-old woman undergoes surgery for a large intraosseous mass involving her C2 vertebral body.
A biopsy was previously performed and showed cords of cells that were positive for CK8, CK18, EMA, S-100, and brachyury and negative for CK7 and CK20.
Which is the single most sensitive and specific immunohistochemical marker for this malignancy?
A. Cytokeratin 8
B. Epithelial membrane antigen (EMA)
C. S-100 Brachyury