Multiple involvement of the central nervous system in Rosai-Dorfman disease.

Rosai-Dorfman disease is a rare, benign, idiopathic histio-proliferative disorder. Only 5% of cases involve the central nervous system. We describe a 10-year-old girl with pain in her lower limbs and back. Spinal magnetic resonance imaging revealed an intradural extramedullary lesion at T9-T10. We decided on surgical treatment. An anatomic/pathologic examination revealed histiocytic-like cells and extensive fibrosis. Immunohistochemistry revealed positivity for CD68 protein and negativity for CD1a protein. Craniospinal magnetic resonance imaging demonstrated an extra-axial lesion in the right frontal region, a small nodule in the left middle cerebellar peduncle, and another small lesion in the right ventral pons. We performed a complete removal of the frontal lesion. The histologic examination produced results compatible with Rosai-Dorfman disease. Most lesions in intracranial Rosai-Dorfman disease mimic meningioma. The definitive diagnosis relies on pathologic and immunohistochemical characteristics. Surgical removal is generally regarded as the treatment of choice. Disease progression after surgical resection is uncommon. Surgical treatment is not recommended until clear disease progression is detected, or focal disease causes neurologic compression. This disease must be included in the differential diagnosis of lesions that mimic meningioma.