[Oral squamous cell carcinoma and lichen planus vs. lichenoid lesions. Case report].

Background: The development of squamous cell carcinoma from oral lichen planus is controversial. We report a case of intraoral squamous cell carcinoma, which presents together with lesions of oral lichen planus. The aim of this report was to analyze the problem to distinguish between the incipient changes of squamous cell carcinoma from the features described in oral lichen planus, in order to establish an accurate diagnosis of both entities.

Clinical Case: A 57-year old man with a history of smoking and chronic alcohol intake, who had an ulcerated tumor mass located in the tongue, and bilateral white reticular patches on buccal mucosa and borders of the tongue. The histopathological report was moderately differentiated invasive squamous cell carcinoma and lichen planus respectively.

Conclusions: The premalignant nature of OLP is still indeterminate and controversial, this is primarily due to inconsistency in the clinical and histological diagnostic criteria used to differentiate cases of oral lichen planus from lichenoid reactions or other lesions causing intraepithelial dysplasia with high potentially malignant transformation. Oral lichenoid reactions are possibly most likely to develop malignant transformation as compared to the classic OLP lesions.