Pseudo oral hairy leukoplakia in a renal allograft recipient.

Oral hairy leukoplakia (OHL) is a disorder of the tongue associated with Epstein-Barr virus (EBV). OHL is seen mainly in HIV infection but is also rarely seen in the course of iatrogenic immunosuppression, especially in kidney transplantation; OHL is even more rarely seen in immunocompetent hosts. Lesions that clinically and histologically mimicked OHL but were not associated with EBV were recently characterized as pseudo hairy leukoplakia. We present such a case that occurred in a renal allograft recipient; light and electron microscopy, immunohistochemistry, and in situ hybridization were used to examine the patient for the presence of EBV and human papillomavirus. Two independent treatments with topical retinoid and oral amoxicillin resulted in complete remission. Pseudo hairy leukoplakia may correspond, at least in some cases, to the conditions known as leukoedema and white sponge nevus; the distinction of these diseases from OHL is of importance because OHL is a hallmark of severe immunosuppression.