A report of intracranial Rosai-Dorfman disease with literature review.

Rosai-Dorfman disease (sinus histiocytosis with massive lymphadenopathy), is a rare benign histiocytic proliferative disorder. Over 650 cases have been reported since 1969. To the best of our knowledge, there have been only 31 cases with central nervous system involvement reported in the literature. Intracranial disease usually presents clinically and radiologically as a "meningioma". It can be misdiagnosed as a nonspecific inflammatory process because of the atypical histologic features of Rosai-Dorfman disease occurring in a non-nodal location. Familiarity with such atypical histologic features and appropriate use of immunohistochemical stains is required for a definitive diagnosis of central nervous system Rosai-Dorfman disease. We report such an intracranial lesion with other extranodal sites of involvement with a 5-year follow up and a review of previously reported cases. Ann Diagn Pathol 5:96-102, 2001.