Background: Oral lichen planus (OLP) is a common immune-mediated chronic inflammatory disease affecting the oral mucosa. It is most likely to occur in adults, particularly in women. The most commonly affected areas are the buccal mucosa, tongue and gingiva, either alone or in combination. The aim of this study was to analyse the clinicopathological characteristics of gingival lichen planus in a series of patients diagnosed between 2000 and 2019.

Materials and method: Files of 190 patients with histopathologically confirmed gingival lichen planus were retrieved from the archives of the Laboratory of Oral and Maxillofacial Pathology of the Geneva University Hospitals. We analysed the demographic characteristics of the patients, the location, clinical presentation and histopathological characteristics of the lesions, and the presence of symptoms.

Results: The majority of the patients were women (74.2%). The age ranged between 12 and 88 years of age, with a mean of 58.6 years. 79 cases (41.6%) of gingival lichen planus were confined to the gingiva. In the remaining cases, the gingival lesions were associated with other localisations, mostly the buccal mucosa and the tongue, as well as other intraoral and extra-oral sites. 38.7% of the patients presented mixed form of OLP, 27.8% keratotic form and 22.4% erythematous/erosive form. The mixed and the erythematous/erosive forms were the most symptomatic lesions. The majority of gingival lichen planus were active atrophic. A total of seven malignant transformation were found (3.7% of the cases).

Conclusion: Gingival lichen planus is a chronic disease that can have many different clinical and histological presentations. Long-term regular follow-up of gingival lichen planus is recommended to detect signs of malignant transformation.