Management Strategies of Plasma Cell Granuloma Involving the Central Nervous System: A Systematic Review of the Literature

Background: Plasma cell granuloma (PCG) is a rare clinical entity seen in the neurosurgical literature. It has often been referred to as inflammatory myofibroblastic tumor or inflammatory pseudotumor. No well-defined management guidelines exist in the literature. Methods: Using PRISMA guidelines, we systematically reviewed the literature in PubMed and Google Scholar using MeSH terms: intracranial plasma cell granuloma, myofibroblastic tumor, intracranial pseudotumor, spinal plasma cell granuloma. We analyzed the clinical presentation, treatment strategies, clinical outcomes, and follow-up across different studies. Results: Eighty-three studies were included presenting 108 cases. Primary extracranial disease was seen in 4 patients and primary central nervous system (CNS) disease in 104. In the combined cohort, multicompartmental disease was seen in 22 (20.8%) patients. Headache (n=40, 42.59%) was the most common clinical symptom. Surgical excision (n=86, 79.6%) was the most common primary treatment used. Radiation therapy, steroids, and chemotherapy (methotrexate/6-mercaptopurine/rituximab) were also used. Disease recurrence was noted in 25 (33.3%) patients and residual disease in 33 (30.5%). Mortality was seen in 4 (3.7%) patients. In the cranial PCG subgroup (n=87), 81 (93.1%) patients had solitary lesions, and 6 (6.8%) had multiple lesions. Recurrence after primary surgery was noted in 27.58% (n=24). In the spinal PCG subgroup (n=17), the thoracic spine was the most common location (n=9, 52.9%) and recurrence was seen in 5.84% (n=1). Conclusions: Combination of multiple treatment modalities is needed when approaching this complex disease. Spinal PCGs respond favorably to gross total excision, with a low recurrence rate. Cranial PCGs warrant intense follow-up with secondary chemotherapy/radiation/steroids in recurrent cases.