[Leukoplakia of the upper urinary tract].

Leukoplakia is a morphological term that attempts to define keratinizing desquamative squamous metaplasia of the transitional epithelium. It is uncommon in the upper urinary tract (less than 100 cases have been reported) and has been attributed to infection or mechanical injury to the epithelium and/or genetic factors. We present a case of leukoplakia in a male patient with renal tuberculosis that had been in remission for the past 15 years. Eight years earlier he had intermittently passed keratin laminas (pathognomonic of leukoplakia) during the course of various episodes of nephritic colic. After discarding a reactivation of tuberculosis and malignancy of the metaplastic lesion, we continued conservative treatment with radiologic and cytologic control evaluations.