Primary Central Nervous System Lymphoma
Primary central nervous system lymphoma (PCNSL) is an aggressive type of lymphoma that begins in the brain, eyes, leptomeninges or spinal cord and does not spread to other parts of the body. The large majority of cases are diffuse large B-cell lymphoma in histology. Treatment is based not on surgical resection but on high-dose methotrexate-based chemotherapy.
最終更新: 2026-06-06
Definition
Primary central nervous system lymphoma is an aggressive non-Hodgkin lymphoma confined to the central nervous system. It accounts for roughly 2-3% of all brain tumors, and about 90% of cases are of the diffuse large B-cell lymphoma (DLBCL) type. Unlike systemic (body-wide) lymphoma, the disease is limited to the brain, eyes, cerebrospinal fluid and spinal cord.
Epidemiology and Risk Factors
In patients with a normal immune system it usually occurs around the ages of 60-70. The most important risk factor is immunosuppression; HIV/AIDS, immunosuppressive therapy after organ transplantation, and congenital immune deficiencies markedly increase the risk. In immunosuppressed patients the disease may appear at a younger age and is often associated with the Epstein-Barr virus.
Symptoms
Symptoms often progress over weeks. The most common features are location-dependent focal neurological deficits (weakness, speech disturbance, balance problems), personality and behavioral changes, cognitive decline, headache from raised intracranial pressure and, less commonly, seizures. Patients with ocular involvement may have blurred vision and floaters.
Diagnosis
Contrast-enhanced brain MRI typically shows one or more periventricular lesions that enhance homogeneously and strongly and show restricted diffusion; a butterfly appearance involving the corpus callosum is characteristic. Definitive diagnosis is made by stereotactic biopsy. Importantly, steroids can rapidly shrink the tumor (ghost tumor); therefore, if biopsy is planned, steroids should be avoided beforehand if possible. Immunohistochemistry (CD20 positivity) and molecular tests (MYD88, CD79B) aid diagnosis and prognosis, and cell-free DNA (cfDNA) analysis in the cerebrospinal fluid is an emerging diagnostic method. Whole-body staging is performed to exclude systemic lymphoma.
Treatment Options
Surgical resection is not indicated in PCNSL; the role of surgery is only to provide a tissue diagnosis by biopsy, because the tumor is sensitive to chemotherapy and radiotherapy. The basis of induction therapy is high-dose methotrexate, which can cross the blood-brain barrier, usually combined with agents such as rituximab. In suitable patients who respond to induction, options for consolidation include autologous stem cell transplantation or low-dose whole-brain radiotherapy. For cases with certain molecular features or relapse, newer approaches such as BTK inhibitors, immunomodulatory agents and, in selected cases, CAR-T cell therapy are used.
Prognosis
Prognosis varies with age, performance status, involvement of deep structures and molecular features. Prognostic scoring systems combining these factors (MSKCC, IELSG) are used to estimate the course. High-dose methotrexate-based treatment and consolidation approaches can achieve long-term remission in a proportion of patients; newer targeted and cellular therapies are promising in relapsed disease. The long-term neurotoxicity risk of treatment must be considered, particularly in older patients. Outcomes vary individually and no outcome can be guaranteed.
参考文献
- Greenberg MS. Greenberg's Handbook of Neurosurgery. 10th ed. Thieme; 2023:840-848.
- Osborn AG, Hedlund GL, Salzman KL. Osborn's Brain: Imaging, Pathology, and Anatomy. 2nd ed. Elsevier; 2018:732-750.
- Hoang-Xuan K, et al. European Association of Neuro-Oncology (EANO) guidelines for the diagnosis and treatment of primary CNS lymphoma. Lancet Oncol. 2023.
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