Central nervous system involvement in Rosai‐Dorfman disease: Report of a case with a review of the literature

A 55‐year‐old woman had Rosai‐Dorfman disease (RDD) forming multiple masses of abnormal histiocytes, three in the cranial cavity and one in the left orbit that was proptotic. The masses were removed and found to consist of abnormal histiocytes that were immunoreactive to cluster designation 68 (CD68) (KP‐1), alpha‐1‐antitrypsin and S‐100 protein and showed emperipolesis. A review of 28 cases of RDD, including this instance, revealed a ratio of 5:2 between males and females and a mean age of 32 years. Intracranial involvement was much more frequent than that of the spinal cord. Histologically, central nervous system (CNS) RDD must be distinguished from meningioma, Langerhans cell histiocytosis, and plasma cell granuloma. Surgical extirpation appears to be the treatment of choice for this idiopathic histiocytic proliferative disorder of the CNS in comparison with radiotherapy and steroid treatment, which have also been tried.