Complete remission of intracranial lymphocytic vasculitis following resection: illustrative case.

backgroundLymphocytic vasculitis (LV), a histopathological subtype of primary angiitis of the CNS, is a rare inflammatory disorder that often presents as mass-like lesions mimicking malignant brain tumors. Owing to its rarity, the characteristics of LV remain poorly understood. OBSERVATIONS: The authors report the case of a young woman who presented with progressive headache. MRI revealed a solitary, ring-enhancing lesion with marked perifocal edema. Fluorodeoxyglucose positron emission tomography (FDG-PET) demonstrated relatively low uptake at the lesion margin, whereas fluciclovine-PET showed mild uptake. Given the high intracranial pressure and uncertain diagnosis, gross-total resection was performed. Histopathological analysis confirmed LV, characterized by perivascular lymphocytic infiltration, fibrin exudation, and the absence of neoplastic or demyelinating features. The patient did not receive additional immunosuppressive therapy and remained disease free for 12 months. LESSONS: To the best of the authors' knowledge, this is the first reported case of a solitary intracranial LV that was successfully managed with resection alone. This case suggests that resection may be a possible therapeutic option for select patients, particularly those with solitary lesions and negative autoimmune profiles. FDG-PET and fluciclovine-PET with MRI may provide supportive information for distinguishing LV from malignant neoplastic tumors. https://thejns.org/doi/10.3171/CASE25705.