Rosai-Dorfman disease presenting as a kidney tumour.

An 81-year-old Caucasian lady studied for anaemia presented with a large solid enhancing mass arising from the hilum of the left kidney on computed tomography scan. A laparoscopic left radical nephrectomy was done through a retroperitoneal approach. Microscopy and histochemistry classified it as Rosai-Dorfman disease though there was neither lymphadenopathy anywhere nor lymphocytosis. It was a very unusual urological presentation of a rare disease.