The immunohistochemical detection of involucrin in denture induced fibrous inflammatory hyperplasia of oral mucous membrane.

Involucrin is a major structural protein specific to the cross-linked cell envelope found in the stratum corneum of stratified squamous epithelium. This protein is considered to be an excellent immunohistochemical marker of normal squamous differentiation. Detection of variations to the patterns of immunostaining for involucrin may also be of value in the differential diagnosis between benign and malignant lesions. Previous studies of involucrin expression in oral mucosa have failed to clarify the effect of chronic inflammatory change upon the patterns of immunoreactivity. This study investigated involucrin staining patterns in fibrous inflammatory hyperplasia of oral mucous membrane (FIH). The results suggest that in FIH an altered pattern of involucrin immunostain occurs in areas of severe inflammatory change. This may reflect changes to the pattern of squamous differentiation in this tissue.