Atypical presentation of fulminant primary central nervous system angiitis

Primary Angiitis of the Central Nervous System (PACNS) is a rare cause of CNS vasculitis that should be included as part complete differential diagnosis, especially in cases with suggestive imaging findings and an absence of secondary causes for CNS vasculitis.

We describe a case of a 47-year-old previously healthy Caucasian male presenting with rapid progression of encephalopathy and fevers. Extensive infectious, autoimmune, and imaging workups were unrevealing. A diagnosis of PACNS was made posthumously on histopathology.

PACNS is a challenging diagnosis owing to frequent discrepancies between radiologic and histopathologic findings. Tissue biopsy is key to diagnosing PACNS.