Pityriasis rubra pilaris heralding diagnosis of urothelial carcinoma: a case report.

Pityriasis rubra pilaris is a papulosquamous inflammatory dermatosis that can be associated with HIV, autoimmunity, infections, certain medications, and neoplasms. Paraneoplastic pityriasis rubra pilaris has previously been reported in association with solid organ malignancies and once with leukemia. Herein, we present an elderly man with paraneoplastic pityriasis rubra pilaris, heralding the diagnosis of low-grade papillary urothelial carcinoma. Our patient's pityriasis rubra pilaris resolved after surgical resection of the tumor.