This is an example of keratin positive cells in a lymph node from a patient with breast cancer; no diagnostic metastatic carcinoma was seen with H&E stains of this sentinel lymph node.  The first picture on the left shows the subcapsular sinus histiocytes in an H&E stained level.  The middle picture is a scanning view of the keratin stain with single, positive staining cells in the subcapsular sinus.  The picture on the right is a high power, showing keratin staining of cytoplasm and staining of the nucleus with a counterstain indicating it is a cell and not artifact.