MR imaging of cerebral involvement of Rosai-Dorfman disease: a single-centre experience with review of the literature.

Rosai-Dorfman disease (RDD) is a rare, benign, non-Langerhans cells histiocytosis with massive lymphadenopathy of uncertain aetiology. It is commonly characterized by massive, painless, non-tender, bilateral cervical lymphadenopathy. Extra-nodal involvement is usually seen in 50% of patients, with the brain being affected in only 5% of cases, usually as dural-based lesions. Clinical presentation is heterogeneous and strongly dependent on the localization of the lesions. Although the histopathological findings are essential for the final diagnosis, brain magnetic resonance imaging (MRI) currently represents the first-line strategy for the detection of the lesions across the central nervous system (CNS); moreover, it may provide additional elements for the differential diagnosis versus other more common lesions. We performed a case-based literature review to highlight possible aetiologic and pathogenetic theories of this disease, along with imaging features of RDD, with a particular focus on the MRI characteristics of the CNS involvement (CNS-RDD). Finally, we provided a novel insight on the current therapeutic approaches, either surgical or medical.