Evaluation on Malignant Transformation of Oral Lichen Planus

Objective:To evaluate the malignant transformation of oral lichen planus(OLP).Methods:The malignant transformation of oral lichen planus was investigated between 1995 and 2002.The symptoms,the location of lesions,clinical history and histopathological feathers were carefully recorded.Results:5 cases had concurrent or subsequent oral squamous cell carcinoma (SCC),1 case developed verrucous carcinoma in the lower lip,3 patients were epithelial dysplasia histopathologically. In addition,7 patients were in an area of pre-existing OLP,1 in other site, in 1 case the diagnosis of OLP and SCC was synchronous.The malignant transformation occurred most frequently in the erosive and atrophic forms of OLP,and in the buccal mucosa, tongue or gingiva.According to the criteria of diagnosis and malignant transformation of OLP we established, 4 of the 9 patients were considered to develop malignant transformation.Conclusions:These data suggest the probability of some cases of at least OLP having an intrinsic property predisposing to malignant transformation.It is necessary to follow-up the patients regularly two to four times annually and to find early signs of malignant transformation.Follow-up are particularly important in patients with erosive and atrophic OLP,especially when involving the buccal mucosa, tongue and gingiva.