Hematoxylin-eosin staining and immunohistochemistry with Cytokeratin 7.
(A) Hematoxylin-eosin staining in a higher magnification reveals atypical tumors cells with high-grade dysplasia and a high proliferation rate (arrow). (Original magnification, x 100).
(B) Immunohistochemical staining of the tumor shows ubiquitously positive results for Cytokeratin 7 (CK7) as marked in brown color indicating a highly malignant behavior of the tumor. (Original magnification, x 25).