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Nasopharyngeal carcinoma (NPC) constitutes the most common epithelial malignancy of the nasopharynx and shows a strong geographic variation. The histologic appearances of this carcinoma are varied, ranging from squamous cell carcinoma to undifferentiated carcinoma, sometimes with different patterns present within the same tumor. There is a strong association of all hislologic subtypes of NPC with the Epstein-Barr virus, which allows the use of immunohistochemistry and in situ hybridization studies for the diagnosis of NPC. Immunohistochemical stains for keratin are useful for the exclusion for lymphoid tumors which may clinically mimic NPC.