Imaging diagnostic features of intracranial primary extranodal Rosai-Dorfman disease: Two case reports and literature review.

In this report, we describe 2 cases of rare intracranial extranodal Rosai-Dorfman disease. The occurrence of this type of non-Langerhans cell histiocytosis in the central nervous system is infrequent, with less than 5% of cases. The first patient was a 35-year-old male who presented with recurring headaches, and the second patient was a 50-year-old male who reported sudden onset of dizziness and vomiting. Computed tomography scans were performed in both cases, but magnetic resonance imaging played a crucial role in the characterization of the lesions and their locations in the thalamus, third ventricle, lateral ventricles, and cerebellopontine angle area. The final diagnosis was confirmed through pathological examination and immunohistochemistry following brain tumor resection. These cases underscore the significance of magnetic resonance imaging in the early diagnosis of intracranial extranodal Rosai-Dorfman disease.