Rosai-Dorfman-Destombes Disease With CNS Involvement: From Treatment Response to Maintenance Strategy and Insights Into Systemic Inflammatory Dysregulation.

Rosai-Dorfman-Destombes disease (RDD) is a rare non-Langerhans cell histiocytosis with heterogeneous clinical presentations and an incompletely understood pathophysiology. While often indolent, a subset of patients develops aggressive, multisystem disease requiring systemic therapy, particularly in the presence of CNS involvement. We report the case of a 63-year-old male patient with disseminated RDD, including CNS lesions, marked systemic inflammation, and biclonal gammopathy at diagnosis. Initial treatment with vinblastine and dexamethasone induced complete clinical and radiological remission, which was sustained for three years under a maintenance regimen with vinblastine. Disease relapse was characterized by recurrent multisystem involvement, including pulmonary, sinonasal, and CNS lesions, and was complicated by pulmonary embolism in the absence of conventional risk factors. Retreatment with corticosteroids led to rapid clinical improvement, followed by maintenance therapy with methotrexate. This case highlights the potential role of maintenance strategies in achieving durable disease control in RDD, particularly in patients with CNS or multisystem involvement. Furthermore, the association of inflammatory, immunological, and thrombotic manifestations supports the concept of RDD as a systemic inflammatory dysregulation disorder, with implications for disease monitoring and therapeutic decision-making.