Detection of the Epstein-Barr virus (EBV) by in situ hybridization as definitive diagnosis of hairy leukoplakia.

Histopathological findings in cases of hairy leukoplakia (HL) are not exclusive to this lesion. A total of 36 tissue samples from patients previously diagnosed with HL based solely on morphological aspects were used in this study. Our purpose was to confirm the presence of Epstein-Barr virus (EBV) in these tissue samples by in situ hybridization (ISH), and to compare the detection of EBV with specific histopathological findings observed in each case. Among the 36 specimens, 80.55% were EBV positive, confirming the previous clinical and histhophatological diagnosis. None of the histopathological findings analyzed correlated with the presence or absence of EBV. This shows that a definitive diagnosis of HL cannot be established based on histopathological findings alone. Because there are many important implications on the establishment of definitive diagnosis of HL, the detection of EBV by ISH is obligatory.