Rosai-Dorfman disease – Isolated intracranial localization: A case report and literature review

• Histopathology and immunohistochemistry images (H&E, S100, CD68) support the diagnosis. • Intraoperative findings include detailed tumor consistency and vascularity. • Historical data moved to the Introduction; discussion focuses on case-specific findings. Rosai-Dorfman Syndrome – Sinus histiocytosis is a benign disease with idiopathic etiology, primarily presenting with cervical lymphadenopathy and a febrile-intoxication syndrome but it can also affect other organs and systems such a skin, bones, orbit, central nervous system. Isolated intracranial localization is rare. It occurs more frequently in children and young adults but it can affect individuals of any age. In this article, we present a clinical case of a 67-year-old woman with a clinical picture of sudden-onset speech disturbances and a generalized tonic-clonic seizure. Imaging studies revealed an intracranial mass located in the left parietal region, appearing as a meningioma. Cytological and immunohistochemical examinations demonstrated an infiltrate of lymphocytes, plasma cells, and histiocytes expressing protein S-100 and CD68. Also described is the phenomenon of emperipolesis – the presence of intracytoplasmic lymphocytes within histiocytes.