Pathology and immunohistochemistry
Thirty-nine (53.4%) patients had a non-keratinizing undifferentiated
(WHO- 3 classification) on their pathological examination, followed by
32 (43.8%) patients with non-keratinizing differentiated disease (WHO-
2), and only two patients presented with a keratinizing NPC (2.7%)
(WHO- 1). EBER staining for the presence of Epstein Barr Virus (EBV) was
positive in 38 samples (52.1%). Proliferation marker Ki-67 was
58.6%±22.7% in our study.