Pure sarcoma should be diagnosed only after thorough sectioning and with negative stains for p63, broad spectrum keratin and high molecular weight keratin
Spindled component may be positive for high molecular weight keratin or p63
Stromal component negative for high molecular weight keratin and p63
Epithelial component is malignant
Epithelial component is benign
Squamous differentiation may be present
No squamous differentiation
Nodular fasciitis is very rare in the breast and should be diagnosed only after thorough sectioning and with negative keratin stains (including high molecular weight keratin)
Fibromatosis is very rare in the breast and should be diagnosed only after thorough sectioning and with negative keratin stains (including high molecular weight keratin)
Pleomorphic adenoma is very rare in the breast and does not have infiltrating margins and the epithelial component is not malignant
