Fig. 1.

(a) In nasopharyngeal carcinoma, the two components are mixed. Tumor cells of low maturation level, as in the presented tissue sample, are distributed/infiltrating the stroma, which is rich in lymphocytes. Hematoxylin and eosin staining, primary objective magnification 20×. (b) In this example, by means of immunohistochemical procedures with cytokeratin markers (CK 5/6), the squamous cell carcinoma component is made clearly visible against a dense lymphocytic infiltrate. Primary objective magnification 10×.