Mitomycin C therapy for corneal intraepithelial neoplasia masquerading as limbal stem cell deficiency with recurrent epithelial defect.

Diagnosis of corneal intraepithelial neoplasia was missed in a patient who presented with recurrent large epithelial defects with pannus. The patient was eventually diagnosed and successfully treated with topical mitomycin C. Mitomycin C may be preferable to surgery in lesions with extensive corneal involvement. Impression cytology should be used for early diagnosis in suspicious lesions.