Rosai-Dorfman disease mimicking chronic subdural hematoma.

Rosai-Dorfman disease (RDD), otherwise known as sinus histiocytosis with massive lymphadenopathy, is an uncommon, benign systemic histio-proliferative disease characterised by massive lymphadenopathy particularly in the head and neck region, and is often associated with extra-nodal involvement. We report a case in which RDD was mistaken for a chronic subdural hematoma and surgery was attempted.