A Rare Neuromyelitis Optica Mimic: Primary CNS Histiocytic Sarcoma

Objective NA. Background Design/Methods Results Primary CNS histiocytic sarcoma is a rare hematolymphoid malignancy with features of mature histiocytes and carries poor prognosis. We describe unique case in which 50-year-old woman presented recurrent acute brainstem syndrome, area postrema myelitis corresponding MRI lesions meeting diagnostic criteria for seronegative NMOSD. Despite initial improvement steroids plasma exchange, she experienced symptoms over ten months referable to new persistently enhancing lesions. At autopsy, neuropathology revealed diffusely infiltrative primary sarcoma. This represents clinicoradiologic mimic NMOSD, underscoring the importance evaluation diseases cases atypical Conclusions