Redefining the Prevalence of Dural Involvement in Rosai-Dorfman Disease of the Central Nervous System.

Background: Sinus histiocytosis with massive lymphadenopathy, also known as Rosai-Dorfman disease, is a rare condition, classically characterized by painless, massive cervical lymphadenopathy. Histologically, the pathognomonic findings include a dense, mixed inflammatory infiltrate with areas of emperipolesis. Albeit infrequent, when Rosai-Dorfman disease affects the central nervous system, it typically manifests as an isolated dural lesion, often mimicking a meningioma. A purely intraparenchymal manifestation of Rosai-Dorfman disease of the brain and spine with absent dural involvement is exceedingly rare.

Case Description: In this report, we describe a 59-year-old woman who underwent surgical excision of an intraparenchymal cerebellar lesion. Histologic analysis of the resected specimen diagnosed isolated Rosai-Dorfman disease with absent systemic involvement. We also provide an updated review of the literature of nondural-based Rosai-Dorfman disease in the central nervous system.

Conclusions: With the recent increase of such reported cases, it becomes imperative that Rosai-Dorfman be considered more than as a dural lesion that may mimic meningioma. Diagnostic and therapeutic challenges surrounding this disease entity are also discussed.