Involucrin expression in some oral lichenoid lesions.

The aim of this investigation was to assess the reproducibility of a study which reported that involucrin could be used as a diagnostic marker in oral lichenoid lesions. Twenty-eight formalin-fixed, paraffin-embedded specimens were examined. They included tissue from 13 patients with lichen planus, 11 with drug-related lichenoid reactions, one with dysplasia in a lichenoid lesion and three with normal oral mucosa. In each case the biopsy site was the buccal mucosa, PAS stained smears for fungi were negative and immunofluorescence results supported the diagnosis. An immunoperoxidase technique was used to demonstrate involucrin reactivity. In all sections there was consistent positive staining for involucrin in the superficial layers of the epithelium and all the basal layers were negative. In conclusion there were no demonstrable differences in the involucrin reactivity between the different lesions.