Diagnosis and Treatment of Primary Central Nervous System Lymphoma

Abstract

Primary central nervous system lymphoma（PCNSL）accounts for approximately 5％ of primary brain tumors and its incidence has been increasing recently, especially in the elderly. Most PCNSLs are histologically large B‒cell non‒Hodgkin’s lymphomas, occurring in solitary or multifocal lesions in the brain, and growing rapidly. Biopsy is the gold standard for establishing the diagnosis and classification of PCNSL, but it is relatively invasive and difficult to perform in some cases. Differential diagnosis by means of imaging such as MRI and PET is not always easy, because it often closely resembles other malignant brain tumors and inflammatory diseases. In recent years, new diagnostic techniques have been attempted, such as the detection of IL‒10, a cytokine and chemokines, and the detection of MYD88 or CD79B gene mutations using cell‒free DNA in cerebrospinal fluid. Multidrug chemotherapy（rituximab, high‒dose methotrexate, procarbazine, vincristine followed by high‒dose cytarabine；R‒MPV‒A therapy）has been effective in treating patients and significantly prolongs survival. However, no treatment has been established for recurrent or refractory PCNSL. BTK（Bruton’s tyrosine kinase）inhibitors, which were approved by insurance in 2020, are expected to be incorporated with re‒challenges of chemotherapy and radiation therapy. High‒dose chemotherapy, combined with autologous hematopoietic stem cell transplantation, is also considered an important treatment strategy for young patients.