Tumefactive primary angiitis of the central nervous system mimicking glioblastoma: A case-based systematic review.

Background: Primary angiitis of the central nervous system (PACNS) is an uncommon inflammatory condition that affects small- to medium-sized central nervous system vessels. Diagnosis remains challenging owing to the nonspecific clinical and radiological characteristics that frequently reflect glioblastoma or other neurological disorders. This study presents a case of a solitary tumefactive PACNS lesion initially misdiagnosed as glioblastoma. We also conducted a systematic analysis to assess the diagnostic variability, clinical-radiological characteristics, and treatment outcome. Methods: A 42-year-old woman with a 20-year history of migraines presented with unusual headaches for 6 weeks. Magnetic resonance imaging (MRI) scan findings indicate a right parietal lesion diagnosed initially as glioblastoma. Following minicraniotomy and resection, histopathological examination revealed PACNS. A Preferred Reporting Items for Systematic Review and Meta-Analysis-guided systematic review of published cases from 2000 to 2023, identified 34 tumor-like PACNS cases that exhibited characteristics similar to glioblastoma. Demographic data, predictive diagnostic imaging factors, histology, and management were collected and examined. Results: The review revealed a mean age of 35.92 years (range: 5-68 years), with a nearly equal sex distribution. Common symptoms included focal neurological impairments (71%), seizures (26%), and headaches (19%). MRI revealed T2 hyperintense lesions (87% with edema), which were frequently misinterpreted as glioblastoma owing to mass effect (68%). Magnetic resonance angiography was insensitive (48% abnormal). Histopathology identified lymphocytic (81%) or granulomatous (16%) vasculitis. Steroids (100%) were used in combination with cyclophosphamide (61%) or mycophenolate (23%). Relapses occurred in 26% of the cases, whereas 74% responded to therapy. Delayed diagnosis was associated with persistent impairment (29%). Conclusion: Tumefactive PACNS lesions frequently exhibit radiographic characteristics similar to glioblastoma, necessitating histological confirmation for accurate diagnosis. Immunosuppression is effective; however, standardized protocols are lacking. Despite the improvement in MRI predictive factors, future studies should investigate blood and cerebrospinal fluid biomarkers, advanced imaging, and conduct multicenter trials to enhance the diagnosis and treatment of this rare condition.