Primary central nervous system lymphoma of the brain stem responding favorably to radiosurgery: A case report and literature review

Objective: To explore various therapeutic alternatives and evaluate the clinical results of patients with primary central nervous system lymphoma (PCNSL). We report a case of PCNSL with involvement of the brain stem managed with radiosurgery using the Leksell gamma knife as the treatment modality. Case Description: A 55-year-old white woman presented with complaints of weakness on the left side of her body and double vision associated with a frontal headache. Nervous system examination revealed right-sided oculomotor palsy and left-sided motor paresis, grade 2/5, in both upper and lower limbs. Her Karnofsky performance score was 50. A contrast-enhanced magnetic resonance imaging scan of the brain revealed an irregular space-occupying lesion in the pons that enhanced uniformly with gadolinium. A frame-based stereotactic biopsy was performed revealing a B-cell malignant lymphoma. Subsequently, stereotactic radiosurgery using the Leksell gamma knife was performed. A dose of 11 Gy was delivered to the tumor margin. A follow-up magnetic resonance imaging scan after 2 months revealed a 50% reduction in the size of the enhancing lesion. Conclusion: Our own results and limited evidence from the literature suggest stereotactic radiosurgery as a potentially safe and effective treatment option in patients with PCNSL.