Repeated Intravenous Methylprednisolone May Prevent Deterioration of Hypertrophic Pachymeningitis in Rosai-Dorfman Disease.

Rosai-Dorfman disease (RDD) is a rare form of non-Langerhans cell histiocytosis. Although 20% of patients with RDD have spontaneous remission, some cases with central nervous system (CNS) involvement require surgery or systemic treatment. We encountered a case of RDD in which hypertrophic pachymeningitis was diffuse, eliminating the need for surgical intervention. A 72-year-old Japanese man was diagnosed with RDD based on pathological lymph node findings. Repeated intravenous methylprednisolone (IVMP) administration resolved and stabilized the hypertrophic pachymeningitis without any sequelae. If surgery or anticancer medications are contraindicated, repeated IVMP may be a good therapeutic option for CNS-associated RDD.