A 73-year-old male patient was treated for conjunctival in situ carcinoma invading the cornea of his right eye. The patient had been previously operated on for two corneoconjunctival lesions on the same eye (one was a pterygium, the other was simple epithelial hyperplasia) and was regularly followed for a systemic lymphoplasmocytic lymphoma (Waldenström's disease). After a corneoconjunctival excision of the tumor, the histological analysis was performed and established the diagnosis of in situ carcinoma. The tumor recurred a few months later and radiation therapy was then given. No recurrence was observed after this latter treatment.