Abstract: Primary central nervous system lymphoma ( PCNSL) is a rare form of non-Hodgkin lymphoma ( NHL) and has aggressive biological behavior. Due to absence of typical clinical presentation，heterogeneity of pathological morphology and multiple neuroimaging appearance and so on，the immunohistochemistry and molecular biology are of vital importance in accurate diagnosis of PCNSL. The development of regimen based on high-dose MTX leads to significant changes in the PCNSL treatment and it has become a generally recognized regimen. Compared with single radiotherapy, the survival rate has evidently been raised. Early diagnosis and surgical removal of the tumors combined with effective radiotherapy and chemo- therapy are the key to extending survival period and improving living quality of patients with PCNSL.

Key words: Central nervous system neoplasms, Lymphoma, Diagnosis, Therapy