CNS Rosai-Dorfman disease with extensive meningeal and parenchymal involvement, and thrombosis in the venous sinuses followed by secondary multiple hemorrhagic infarcts.
Rosai-Dorfman disease (RDD) was first described as "sinus histiocytosis with massive lymphadenopathy" by Rosai and Dorfman in 1969.The extranodal form occurs in over 40% of patients and central nervous system (CNS) involvement is extremely uncommon in these patients. Most of the reported cases had solitary or multiple dural-based lesions.
Two parts of specialty make this case meaningful. Firstly, in our report the lesions were diffuse and involved not only the dura but also the arachnoid, subarachnoid space, and pia mater. Lesions also developed in the parenchyma of both cerebrum and cerebellum, as well as choroid plexus in the posterior horn of the lateral ventricle. Furthermore, the lesions invaded the venous sinuses, followed by thrombosis and organization, which has not been reported previously.
Secondly, we found fibrous proliferated chordae with inflammatory infiltration in the venous sinuses. It is unclear whether these hyperplastic chordae are congenital abnormal formations or an outcome resulting from the inflammatory cell infiltration caused by RDD. However, we speculate that these abnormally thickened chordae might tremendously decrease the blood flow in the venous sinuses, thus contributing to the thrombosis. CNS RDD may also generate thrombosis, though uncommonly.
In the literature, only one RDD case reported extensive dura and arachnoid mater involvement. In that report, the patient presented with increased chronic intracranial pressure and progressive bilateral visual and hearing impairments. MRI showed diffuse dura involvement and dissemination of the orbit and spine. The CSF revealed persistent high lymphocytic pleocytosis, which led to a worse prognosis. Our case also had abnormal CSF results with excessive erythrocytes. Another case reported subarachnoidal involvement with a normal CSF index that later showed stable. Therefore, we speculate that the CSF may be used as another auxiliary method for diagnosing and assessing the prognosis of CNS RDD.
The authors are grateful to professor Robert Schmidt for his relevant review and Zhi-Li He, Li-Feng Wei, Li-Hong Zhao and Wei-Min Wang for their pathology technological help.
Contributed by Ting-Ting Zhang, Yong-Juan Fu, Yue-Shan Piao, Guang-Zhi Liu, Lei-Ming Wang, Shi-Yun Chen, De-Hong Lu, Xu-Guang Gao