A 5-year-old child presenting with tumor-like primary angiitis of the central nervous system

Introduction:Primary angiitis of the central nervous system(PACNS)is a vasculitis confined to the CNS.A small proportion of the lesions may present as a tumor-like mass,which is rarely seen in children.Case presentation:A 5-year-old girl was admitted to our hospital because of an intermittent headache.Brain imaging suggested a space-occupying lesion in the right cerebral hemisphere.The final diagnosis was PACNS with a lymphocytic pattern by stereotactic brain biopsy.Her condition improved after immunotherapy.Conclusion:Pediatricians should consider the possibility of PACNS when encountering intracranial tumor-like lesions.Early diagnosis of tumor-like PACNS and prompt immunotherapy could improve the long-term prognosis and avoid surgery.