Oral hairy leukoplakia diagnosis by Epstein-Barr virus in situ hybridization in liquid-based cytology

Objective: To establish a definitive diagnosis of oral hairy leukoplakia (OHL) by in situ hybridization for Epstein-Barr virus (EBV) detection with liquid-based cytology (LBC), using the ThinPrep® Pap Test, and to compare its efficacy with the traditional method of performing biopsy.

Methods: Thirty-three individuals divided into three groups were included in this study. Group 1 consisted of 15 human immunodeficiency virus (HIV)-positive patients with a clinical and histopathological diagnosis of OHL on the lateral border of the tongue. Group 2 consisted of 10 HIV-positive individuals with neither OHL nor other oral lesions. Group 3 consisted of 10 immunocompetent HIV-negative individuals with neither OHL nor other oral lesions. For each patient from the three groups, exfoliative LBC was performed on the lateral border of the tongue using ThinPrep. For the patients from group 1, a 6-mm-diameter punch biopsy was obtained from the same anatomic site as the brush collection to confirm the diagnosis of OHL by histopathology with in situ hybridization. Slides were prepared for morphological cellular analysis using Papanicolaou (Pap) staining, and for EBV detection using in situ hybridization.

Results: Thirteen of the 15 patients from group 1 were confirmed on punch biopsy as OHL, providing the gold standard for the study. The sensitivity of LBC followed by a Pap-stained smear was 62% and the specificity was 90%. The sensitivity of LBC followed by in situ hybridization was 100% and the specificity was 100%.

Conclusions: Exfoliative LBC associated with EBV in situ hybridization is a simple, effective and non-invasive diagnostic tool for OHL.