SHM Converge Scientific Abstract ePoster Gallery-Diagnosing Primary Angiitis of the CNS Confounded by Multi-System Pathologies

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This case describes a 56-year-old man with a complex history, including prior hemophagocytic lymphohistiocytosis (HLH) in remission, prior left MCA stroke, motor neuron disease, neuropathy, and restless leg syndrome, who presented with weeks of worsening confusion and generalized weakness, plus months of poor appetite and 30-pound weight loss. Because HLH recurrence and other conditions could explain his symptoms, he underwent an extensive evaluation.<br /><br />Initial studies were not diagnostic: lumbar puncture showed only mild lymphocytic pleocytosis and mildly elevated protein, while bone marrow biopsy and labs did not support HLH relapse. Spine MRI, EMG, and EEG were also non-specific. Brain MRI, however, showed multiple enhancing lesions in the subcortical white matter, leptomeningeal, and periventricular regions, raising concern for possible CNS HLH or another inflammatory process.<br /><br />Given the broad differential, a left frontal lobe brain biopsy was performed. This definitively confirmed primary angiitis of the central nervous system (PACNS), showing perivascular lymphocyte- and histiocyte-rich inflammation with vasculitis and vascular wall injury. PACNS is a rare disorder with an incidence of about 2.4 per 1,000,000 person-years in North America and is often difficult to diagnose because it mimics infections, malignancy, secondary vasculitis, vascular disorders, and other neurologic diseases.<br /><br />The patient was treated with high-dose oral prednisone and intravenous cyclophosphamide, after which his mental status gradually improved. He will continue long-term treatment with outpatient rheumatology follow-up. The case highlights the importance of maintaining a broad differential diagnosis in patients with unexplained neurologic symptoms and prior systemic illnesses, and it emphasizes that brain biopsy can be crucial when noninvasive testing is inconclusive and treatment decisions are high-stakes.

Asset Subtitle

Joyce H. Lee

Meta Tag

Author List Antoni Wojtkowski, Desh B. Nepal, Joyce H. Lee

Category Clinical Vignettes

Concept Primary Central Nervous System Vasculitis

Concept Diagnosis

Concept Differential Diagnosis

Concept Brain biopsy

Concept Corticosteroid

Concept Cyclophosphamide

Distinguished Non-Finalist

Presenter Organization Medical College of Wisconsin

Presenting Author Joyce H. Lee

Track Adult

Keywords

primary angiitis of the central nervous system

PACNS

brain biopsy

vasculitis

confusion

generalized weakness

weight loss

enhancing brain lesions

cyclophosphamide

prednisone

Primary Central Nervous System Vasculitis

Diagnosis

Differential Diagnosis

Brain biopsy

Corticosteroid

Cyclophosphamide