[Rosai-Dorfman disease: Case report].

Rosai-Dorfman disease, also known as sinus histiocytosis with massive lymphadenopathy, is a rare dis order of unknown etiology, generally associated with enlargement of superficial and/or deep lymph nodes. Most patients do not require treatment. We report the case of a 10 month old infant who was admitted with a left cervical tumor of 25 days duration.