Massive precorneal extension of squamous cell carcinoma of the conjunctiva.

A 73-year-old man had only light perception vision from a slowly enlarging fleshy papillomatous mass covering the entire cornea. The lesion was excised completely, leaving a clear corneal bed and 20/25 vision. Histopathologically, the lesion was found to be squamous cell carcinoma in situ with early microinvasion of the basement membrane. Viral studies for human papilloma virus were negative. This case represents a massive superficial involvement of the cornea by squamous cell carcinoma and shows the resistance of Bowman's membrane to tumor penetration.