Retroperitoneal Castlemans disease associated with paraneoplastic pemphigus.

Paraneoplastic pemphigus is a rare dermatologic condition that can occur as a paraneoplastic manifestation of lymphoproliferative disorders, visceral malignancies, Castleman disease and thymomas. In a pediatric age group paraneoplastic pemphigus has a striking association with Castleman disease and has a particularly poor prognosis in this age group. We describe a case of paraneoplastic pemphigus associated with retroperitoneal hyaline vascular variant of Castleman disease with a fatal outcome despite aggressive management.