RESUMEN
Immunohistochemical analysis of C-erb B2 as the second member of epidernal growth factor receptor gene family, was performed using ABC method on 32 paraffin-embedded specimens including nine normal oral mucosa, three oral papilloma, two oral papillomas with dysplasia, five epithelial dysplasia and 13 cases of oral squamous cell carcinoma. The positive immunoreactivity for C-erb B2 was increased in oral papillomas, oral papillomas with dysplasia, epithelial dysplasia and oral squamous cell carcinoma relative to normal oral mucosa. In normal oral mucosa, both keratinized and non keratinized stratified squamous epithelium revealed positive reaction for C-erb B2 mainly cytoplasmic and membranous. The distribution of such positivity was in keratin, granular and superficial auter spinous cell layers [upper half of the epithelium], while predominantly basal and parabasal in non-keratinized stratified squamous epithelium [lower half of the epithelium]. In the submucosa, the positivity was restricted to the muscular tissue