Orbital Rosai-Dorfman disease in a fifty-eight years old woman

Rosai-Dorfman disease [RDD] is rare and characterized by histiocytic proliferation and massive cervical lymphadenopathy. About 40% of patients have extra-nodal involvement. Ophthalmic involvement is seen in 10% of cases. A case of orbital Rosai Dorfman disease in a 58 years old woman is presented here, who was misdiagnosed as orbital inflammatory disease initially. The patient did not respond to a course of oral prednisolone. Then complete surgical excision of the mass was performed and the histopathological examination was consistent with a diagnosis of RDD