The Ljubljana classification - its application to grading oral epithelial hyperplasia

Introduction: The diagnosis, prognosis and treatment of particular pathologic entities of the oral mucosa depend almost exclusively on the histologic changes in the epithelium. The basis for the classification of oral epithelial hyperplastic lesions should be their propensity to progress to invasive cancer. Material and methods: In a retrospective study, 135 biopsies of oral epithelial hyperplastic lesions from 115 patients were classified according to the Ljubljana classification, which has recently been introduced for the grading of laryngeal hyperplastic epithelial lesions. Results: Seventy nine cases (59%) showed simple, 42 (31%) abnormal and 11 (8%) atypical hyperplasia; carcinoma in situ was found in three cases (2%). During the follow-up, ranging from 3 months to 6 years (median 1 year), two cases of atypical hyperplasia progressed to invasive cancer, whereas none of the cases classified as simple or abnormal hyperplasia showed progression. Conclusion: The present study suggests that the Ljubljana classification can be reliably applied for classifying oral epithelial hyperplastic lesions into different risk groups, which is essential for prognosis in order to plan therapy. (C) 2003 European Association for Cranio-Maxillofacial Surgery.