Keratinizing corneal intraepithelial neoplasia.

Corneal intraepithelial neoplasia (CIN) is the term applied by some authors to the spectrum of disease ranging from mild dysplasia to carcinoma in situ. Such lesions usually are associated with dysplastic or neoplastic processes at the limbus or adjacent conjunctiva; isolated corneal dysplasia is rare. Clinically, CIN appears as a geographic, gray, translucent thickening of the epithelium with fimbriated or scalloped borders and lesions often contain scattered white dots. We report a case of intraepithelial neoplasia limited to the cornea that had the unusual clinical appearance of a white plaque, which prompted the misdiagnosis of a calcific scar. Histopathologic examination of the debrided tissue revealed intraepithelial neoplasia and marked hyperkeratosis as the cause of the opacification.