A 36-year-old female presented with acute onset right face and left hemibody numbness/weakness and was found to have scattered subacute right hemispheric infarcts. MRA revealed near occlusion of right ICA terminus with distal reconstitution of right MCA and severe left ACA stenosis. She had been diagnosed with Stage IVB cervical cancer, 9 months prior, and was treated with Cisplatin/Paclitaxel/Bevacizumab for 3 cycles with addition of Pembrolizumab for cycles 4-6, followed by maintenance therapy for 5 cycles prior to presentation. One month prior to presentation she developed immune-mediated gastritis/pancreatitis, leading to the discontinuation of Pembrolizumab and subsequent initiation of a steroid tape.

On comprehensive stroke evaluation, cerebrospinal fluid analysis showed normal protein (20 mg/dL), cell count(2/mm³), negative meningitis panel, and cytology/flow cytometry. Vessel wall imaging revealed extensive concentric vessel wall enhancement in right ICA/MCA. Skin biopsy showed no evidence of intravascular lymphoma. Given high suspicion for ICI-related vasculitis, she was treated with intravenous methylprednisone 1g daily for 5 days. Subsequently, Due to worsening of right hemispheric infarcts, she received cyclophosphamide induction therapy and 5 sessions of plasma exchange over the next 2 weeks. Ultimately she required decompressive hemicraniectomy. She remained clinically stable for the next 2 weeks and was discharged on prolonged steroid taper. At follow-up, she remained clinically/radiographically stable with residual left-sided weakness.