Isolated keratinising corneal ocular surface squamous neoplasia with multifocal recurrence

Corneal ocular surface squamous neoplasia usually begins at the limbus and presents as an avascular translucent sheet over the corneal surface. This case report describes a 67-year-old man with an unusual isolated, keratinous nodular corneal lesion. Slit-lamp examination showed an elevated, avascular, whitish plaque-like lesion at the central cornea surrounded by a normal corneal epithelium, with reduced visual acuity of 20/200 in the right eye. Anterior segment optical coherence tomography displayed a hyper-reflective, thickened epithelium with back shadowing. Histopathology showed keratinising hyperplastic stratified squamous epithelium with parakeratosis and moderate nuclear pleomorphism in lower second/third of epithelium suggestive of moderate dysplasia. His visual acuity returned to 20/20 after surgical excision but he developed multifocal corneal recurrences 6 weeks later, which were successfully managed with seven cycles of topical interferon immunotherapy. There are no recurrences observed at 6 months of follow-up.