Primary central nervous system lymphoblastic B cell lymphoma located at cerebellum in a child: A case report and literature review

Introduction: Primary central nervous system lymphoma (PCNSL) is extremely rare in pediatric population. We reported a case of PCNSL in a 3-year-old girl and reviewed the literature in the past three decades.Case presentation: A 3-year-old girl presented with gait disturbance. A contrast-enhanced magnetic resonance image of the brain showed a solitary bulky mass in the left cerebellar hemisphere, hydrocephalus and cerebellar tonsillar hernia. Surgical resection was performed and the patient was diagnosed with primary central nervous system lymphoblastic B cell lymphoma. Then the patient received regular chemotherapy, including 6 cycles of chemotherapy containing high-dose methotrexate (HD-MTX). The patient remains alive 15 months after the diagnosis with no evidence of active disease, but suffered twice chronic subdural hematoma, which was treated by burr hole drainage.Conclusion: Lymphoblastic B cell lymphoma is a rare histologic subtype of pediatric PCNSL. Chemotherapy containing HD-MTX remains the most effective treatment. The patient should avoid head impact after surgical resection of the tumor to prevent chronic subdural hematoma.