Intracranial dural histiocytosis.

Rosai-Dorfman disease is a common benign lymphomatous disorder that involves the lymph nodes and other solid organs. Neurological involvement is rare, and an isolated intracranial Rosai-Dorfman lesion even rarer. Whether isolated intracranial Rosai-Dorfman lesions should be defined as Rosai-Dorfman disease or intradural histiocytosis remains debatable. Although these intracranial masses may radiologically mimic a meningioma, some have diagnostically specific radiological appearances. Because isolated intracranial Rosai-Dorfman lesions are so rarely described their best treatment is controversial. Most patients described in published reports underwent surgery followed in selected cases by adjuvant radiotherapy. Medical therapies achieve conflicting results. Our two case reports, a patient with isolated dural intracranial Rosai-Dorfman lesions and another with multiple intracranial lesions, both without lymphadenopathy, should be of interest to neuroradiologists and neurosurgeons managing similar cases.