肥厚性硬膜炎に類似したRosai-Dorfman diseaseの1例

Case Report of Rosai-Dorfman Disease Mimicking Pachymeningitis

　Ⅰ．はじめに

Rosai-Dorfman disease は1969年と1972年 RosaiとDorfmanによって記述された偽リンパ腫様病変でsinus histiocytosis with massive lymphadenopathy （SHML）として記載されており^27,28)，リンパ節腫大を特徴とする疾患であるが，中枢神経系の病変も報告されている．われわれは肥厚性硬膜脳炎類似の画像を呈したRosai-Dorfman diseaseの症例を経験し興味ある術前MRIが得られたので報告する．

　Rosai-Dorfman disease (RDD) is a rare idiopathic histioproliferative disease affecting the lymph nodes. Extranodal sites may be involved and occasionally represent the initial or sole manifestation of the disease. Central nervous system manifestations especially are exceedingly rare. We reported a case of isolated,intracranial,dural-based RDD. A 69-year-old male,admitted with a second generalized convulsion,was examined by high-resolution MR images that revealed a thickened,stratified dura in the left frontal region with associated cortical edema. The patient underwent craniotomy with subtotal resection of the lesion. Microscopically,with the cytoplasmic staining against S-100 protein the lesion was shown to consist of proliferative histiocytes exhibiting emperipolesis . The histopathological diagnosis was compatible with RDD. The diagnosis of RDD mimicking pachymeningitis is presented,and the previous reported cases of intracranial RDD are reviewed